Intermediates for the preparation of analogs of halichondrin B

ABSTRACT

Intermediates and methods of their use in the synthesis of analogs of halichondrin B are provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/171,971, filed Jun. 29, 2011, which is a continuation of U.S.application Ser. No. 11/628,396, filed Mar. 28, 2007 (U.S. Pat. No.7,982,060), which claims priority under 35 U.S.C. §371 fromInternational Application No. PCT/US05/019669, filed Jun. 3, 2005, whichclaims benefit of U.S. Provisional Patent Application Nos. 60/576,642,filed Jun. 3, 2004, 60/626,769, filed Nov. 10, 2004, and 60/663,300filed Mar. 18, 2005, the entire contents of each of which areincorporated herein by reference.

TECHNICAL FIELD OF INVENTION

The present invention relates to compounds useful as intermediates inthe synthesis of pharmaceutically active macrolide compounds.

BACKGROUND OF THE INVENTION

The invention relates to pharmaceutically active macrolides, synthesisthereof and intermediates thereto. Halichondrin B is a potent anticanceragent originally isolated from the marine sponge Halichondria okadai,and subsequently found in Axinella sp., Phakellia carteri, andLissondendryx sp. A total synthesis of Halichondrin B was published in1992 (Aicher, T. D. et al., J. Am. Chem. Soc. 114:3162-3164).Halichondrin B has demonstrated in vitro inhibition of tubulinpolymerization, microtubule assembly, beta^(S)-tubulin crosslinking, GTPand vinblastine binding to tubulin, and tubulin-dependent GTP hydrolysisand has shown in vitro and in vivo anti-cancer properties. Accordingly,there is a need to develop synthetic methods for preparing analogs ofHalichondrin B useful as anti-cancer agents.

SUMMARY OF THE INVENTION

As described herein, the present invention provides methods forpreparing analogs of Halichondrin B having pharmaceutical activity, suchas anticancer or antimitotic (mitosis-blocking) activity. Thesecompounds include a compound of formula B-1939:

These compounds are useful for treating cancer and other proliferativedisorders including, but not limited to, melanoma, fibrosarcoma,leukemia, colon carcinoma, ovarian carcinoma, breast carcinoma,osteosarcoma, prostate carcinoma, and lung carcinoma. The presentinvention also provides synthetic intermediates useful for preparingsaid analogs of Halichondrin B.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

The methods and intermediates of the present invention are useful forpreparing various analogs of Halichondrin B as described in, e.g. U.S.Pat. No. 6,365,759 and U.S. Pat. No. 6,469,182 the entirety of which areincorporated herein by reference. These Halichondrin B analogs areprepared generally by the assembly of three fragments F-1, F-2, and F-3,as shown by Scheme I below:

1. Fragment F-1

According to one embodiment, the present invention provides a compoundF-1:

-   wherein:-   each of PG¹ and PG² is independently hydrogen or a suitable hydroxyl    protecting group;-   R¹ is R or OR;-   R² is CHO or —CH═CH₂; and-   each R is independently hydrogen, C₁₋₄ haloaliphatic, benzyl, or    C₁₋₄ aliphatic, provided that when R¹ is OMe then PG¹ and PG² do not    form an acetonide group.

In certain embodiments, R¹ is OR. In other embodiments, R¹ is OR whereinR is hydrogen, methyl, or benzyl.

In certain embodiments, PG¹ and PG² are hydrogen. In other embodiments,one of PG¹ and PG² is hydrogen.

Suitable hydroxyl protecting groups are well known in the art andinclude those described in detail in Protecting Groups in OrganicSynthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley &Sons, 1999, the entirety of which is incorporated herein by reference.In certain embodiments, each of PG¹ and PG², taken with the oxygen atomto which it is bound, is independently selected from esters, ethers,silyl ethers, alkyl ethers, arylalkyl ethers, and alkoxyalkyl ethers.Examples of such esters include formates, acetates, carbonates, andsulfonates. Specific examples include formate, benzoyl formate,chloroacetate, trifluoroacetate, methoxyacetate,triphenylmethoxyacetate, p-chlorophenoxyacetate, 3-phenylpropionate,4-oxopentanoate, 4,4-(ethylenedithio)pentanoate, pivaloate(trimethylacetyl), crotonate, 4-methoxy-crotonate, benzoate,p-benzylbenzoate, 2,4,6-trimethylbenzoate, or carbonates such as methyl,9-fluorenylmethyl, ethyl, 2,2,2-trichloroethyl, 2-(trimethylsilyl)ethyl,2-(phenylsulfonyl)ethyl, vinyl, allyl, and p-nitrobenzyl. Examples ofsuch silyl ethers include trimethylsilyl, triethylsilyl,t-butyldimethylsilyl, t-butyldiphenylsilyl, triisopropylsilyl, and othertrialkylsilyl ethers. Alkyl ethers include methyl, benzyl,p-methoxybenzyl, 3,4-dimethoxybenzyl, trityl, t-butyl, allyl, andallyloxycarbonyl ethers or derivatives. Alkoxyalkyl ethers includeacetals such as methoxymethyl, methylthiomethyl,(2-methoxyethoxy)methyl, benzyloxymethyl,beta-(trimethylsilyl)ethoxymethyl, and tetrahydropyranyl ethers.Examples of arylalkyl ethers include benzyl, p-methoxybenzyl (MPM),3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl,2,6-dichlorobenzyl, p-cyanobenzyl, 2- and 4-picolyl.

In certain embodiments, one or both of the PG¹ and PG² moieties of F-1are silyl ethers or arylalkyl ethers. In yet other embodiments, one orboth of the PG¹ and PG² moieties of F-1 are t-butyldimethylsilyl orbenzoyl. In still other embodiments, both of the PG¹ and PG² moieties ofF-1 are t-butyldimethylsilyl.

According to an alternate embodiment, PG¹ and PG² are taken together,with the oxygen atoms to which they are bound, to form a diol protectinggroup, such as a cyclic acetal or ketal. Such groups include methylene,ethylidene, benzylidene, isopropylidene, cyclohexylidene, andcyclopentylidene, a silylene derivative such as di-t-butylsilylene and a1,1,3,3-tetraisopropyldisiloxanylidene derivative, a cyclic carbonate,and a cyclic boronate. Methods of adding and removing such hydroxylprotecting groups, and additional protecting groups, are well-known inthe art and available, for example, in P. J. Kocienski, ProtectingGroups, Thieme, 1994, and in T. W. Greene and P. G. M. Wuts, ProtectiveGroups in Organic Synthesis, 3^(rd) edition, John Wiley & Sons, 1999.According to another embodiment, PG¹ and PG² are taken together to forman acetonide group.

According to one embodiment, R² is CHO.

According to another embodiment, R² is —CH═CH₂.

In certain embodiments, the present invention provides a compound offormula F-1 having the stereochemistry depicted in compound F-1′:

wherein each variable is as defined above and described in classes andsubclasses above and herein.

In certain embodiments, the following compounds F-1a and F-1b areprovided:

wherein “TBS” refers to t-butyldimethylsilyl.

Details of the syntheses of F-1a and F-1b are set forth in the Examplesinfra.

2. Fragment F-2

According to another embodiment, the present invention provides acompound F-2:

wherein:

-   each    is independently a single or double bond, provided that both    groups are not simultaneously a double bond;-   LG¹ is a suitable leaving group;-   X is halogen or —OSO₂(R^(y));-   R^(y) is C₁₋₆ aliphatic or a 5-7 membered saturated, partially    unsaturated, or fully unsaturated ring, wherein R^(y) is optionally    substituted with up to 3 groups selected from halogen, R, NO₂, CN,    OR, SR, or N(R)₂;-   each R is independently hydrogen, C₁₋₄ haloaliphatic, or C₁₋₄    aliphatic; and-   PG³ is a suitable hydroxyl protecting group.

As used herein, a suitable leaving group is a chemical moiety that isreadily displaced by a desired incoming chemical moiety. Suitableleaving groups are well known in the art, e.g., see, “Advanced OrganicChemistry,” Jerry March, 4^(th) Ed., pp. 351-357, John Wiley and Sons,N.Y. (1992). Such leaving groups include, but are not limited to,halogen, alkoxy, sulphonyloxy, optionally substituted alkylsulphonyloxy,optionally substituted alkenylsulfonyloxy, optionally substitutedarylsulfonyloxy, and diazonium moieties. Examples of suitable leavinggroups include chloro, iodo, bromo, fluoro, methanesulfonyloxy(mesyloxy), tosyloxy, triflate, nitro-phenylsulfonyloxy (nosyloxy), andbromo-phenylsulfonyloxy (brosyloxy). In certain embodiments, the LG¹moiety of F-2 is sulphonyloxy, optionally substituted alkylsulphonyloxy,optionally substituted alkenylsulfonyloxy, or optionally substitutedarylsulfonyloxy. In other embodiments, the LG¹ moiety of F-2 isoptionally substituted alkylsulphonyloxy. In yet other embodiments, theLG¹ moiety of F-2 is mesyloxy or tosyloxy.

In certain embodiments, the X moiety of F-2 is halogen. In otherembodiments, the X moiety of F-2 is sulphonyloxy, optionally substitutedalkylsulphonyloxy, optionally substituted alkenylsulfonyloxy, oroptionally substituted arylsulfonyloxy. In still other embodiments, theX moiety of F-2 is triflate.

In certain embodiments, the PG³ moiety of F-2, taken with the oxygenatom to which it is bound, is a silyl ether. In other embodiments, thePG³ moiety of F-2, taken with the oxygen atom to which it is bound, isan ester group. According to one aspect of the present invention, thePG³ moiety of F-2 is t-butyldimethylsilyl. According to another aspectof the present invention, the PG³ moiety of F-2 is pivaloyl or benzoyl.

In certain embodiments, the present invention provides a compound offormula F-2 having the stereochemistry depicted in formula F-2′:

wherein each variable is as defined above and described in classes andsubclasses above and herein.

In certain embodiments, a compound F-2a or F-2b is provided:

wherein “MsO” refers to mesylate, “TfO” refers to triflate, “OPv” refersto pivaloate, “OBz” refers to benzoate, and “TsO” refers to tosylate.

In other embodiments, the present invention provides a compound offormula F-2b wherein said compound is crystalline. According to anotherembodiment, a compound of formula F-2b is provided wherein said compoundis crystallized from an alkane solvent. In certain embodiments,crystalline F-2b is provided wherein said compound is crystallized frompentane or heptane. In other embodiments, crystalline F-2b is providedwherein said compound is crystallized at about 0° C.

Compounds of formula F-2 are prepared generally from intermediates F-2dand F-2e as shown in Scheme A below.

Accordingly, another aspect of the present invention provides a compoundof formula F-2d:

wherein:R′ is —CH═CH₂ or —C(O)H;Alk is a C₁₋₄ straight or branched aliphatic group; andPG⁵ is a suitable hydroxyl protecting group.

Suitable hydroxyl protecting group PG⁵ is as described and defined forthe PG³ moiety of compound F-2, supra. In certain embodiments, PG⁵,taken with the oxygen atom to which it is bound, is a silyl ether. Inother embodiments, PG⁵ is t-butyldimethylsilyl.

According to one embodiment, the Alk moiety of compound F-2d is methyl.

In certain embodiments, a compound of formula F-2d′ is provided:

Yet another aspect of the present invention provides a compound offormula F-2e:

-   wherein:-   R″ is OH, OPG³, or LG⁴;-   LG⁴ is a suitable leaving group; and-   each PG³ is independently a suitable hydroxyl protecting group,    provided that R″ is other than OMs when PG³ is t-butyldiphenylsilyl.

One of ordinary skill in the art would recognize that the R″ moiety ofcompound F-2e may be transformed from OH to a protected hydroxyl group,OPG³, or, alternatively, directly to LG⁴. Such transformations are knownto one skilled in the art and include, among others, those describedherein. In certain embodiments, R″ is OH or LG⁴. The LG⁴ leaving groupof formula F-2e is as described and defined for the LG¹ moiety ofcompound F-2, supra. In certain embodiments, LG⁴ is tosyloxy ormesyloxy.

The PG³ moiety of compound F-2e is as defined and described for the PG³moiety of compound F-2, supra. In certain embodiments, PG³, taken withthe oxygen atom to which it is bound, is a silyl ether. In otherembodiments, PG³ is t-butyldiphenylsilyl.

Still another aspect of the present invention provides a compound F-2f:

wherein Alk, PG³ and PG⁵ are as defined generally and in classes andsubclasses described above and herein. Compounds of formula F-2f areused to prepare compounds of formula F-2 by methods described herein andthose known in the art.

Details of the synthesis of F-2a are set forth in the Examples infra.

Alternatively, compounds of formula F-2 are prepared from D-quinic acidas shown by Scheme II below. Details of the preparation of compounds offormula F-2 are set forth in the Examples infra.

Yet another method for preparing compounds of formula F-2 from D-quinicacid provides an alternative route from intermediate 12 to intermediate17 as shown in Scheme III below.

Scheme III above shows an alternate method for preparing intermediate 17from intermediate 12 via Eschenmoser-Tanabe Fragmentation, wherein eachR^(x) is independently OPG^(x) or CN wherein PG^(x) is a suitablehydroxyl protecting group as described herein. Intermediate 17 is thenused to prepare compounds of formula F-2 according to Scheme II above.

Still another method for preparing compounds of formula F-2 fromD-quinic acid provides an alternative route from intermediate 9 tointermediate 17 as shown in Scheme IV below.

wherein PG^(y) is a suitable carboxyl protecting group, as describedherein, and each PG^(x) is independently a suitable hydroxyl protectinggroup as described herein.

Yet another method for preparing intermediates useful for preparingcompounds of formula F-2 from D-quinic acid is shown in Scheme V below.

In Scheme V above, intermediate 7 (from Scheme II), wherein R is amethyl ester, is used to prepare ER-817664 as a crystallineintermediate. As depicted in Scheme V above, each PG⁵ and PG⁶ isindependently a suitable hydroxyl protecting group. In certainembodiments, PG⁵ and PG⁶ are taken together to form a cyclic diolprotecting group. In other embodiments, PG⁵ and PG⁶ are taken togetherto form a cyclohexylidene protecting group. As depicted in Scheme Vabove, LG⁵ is a suitable leaving group. Such suitable leaving groups arewell known in the art and include those described herein. In certainembodiments, LG⁵ is mesyloxy or tosyloxy.

According to another embodiment, the present invention provides acompound of formula A:

-   wherein:-   designates a single or double bond;-   n is 1, 2, or 3;-   each of PG⁵ and PG⁶ is independently a suitable hydroxyl protecting    group;-   W is CH-A or C(O);-   A is a C₁₋₆ aliphatic group, wherein A is optionally substituted    with one or more Q¹ groups;-   each Q¹ is independently selected from cyano, halo, azido, oxo, OR,    SR, SO₂R, OSO₂R, N(R)₂, NR(CO)R, NR(CO)(CO)R, NR(CO)N(R)₂, NR(CO)OR,    (CO)OR, O(CO)R, (CO)N(R)₂, O(CO)N(R)₂, or OPG¹, wherein PG¹ is a    suitable hydroxyl protecting group, and wherein:    -   two Q¹ on A are optionally taken together to form a 3-8 membered        saturated, partially unsaturated, or aryl ring having 0-4        heteroatoms independently selected from nitrogen, oxygen, or        sulfur; and-   each R is independently selected from hydrogen or an optionally    substituted group selected from C₁₋₆ aliphatic, a 5-10 membered    saturated, partially unsaturated or aryl carbocyclic ring, or a 4-10    membered saturated, partially unsaturated or aryl ring having 0-4    heteroatoms independently selected from nitrogen, oxygen, or sulfur,    wherein:    -   two R groups on the same nitrogen atom are optionally taken        together with said nitrogen atom to form a 3-8 membered        saturated, partially unsaturated, or aryl ring having 1-4        heteroatoms independently selected from nitrogen, oxygen, or        sulfur.

In certain embodiments, the present invention provides a compound offormula A having the stereochemistry as depicted in formula A′:

wherein each variable is as defined above and described in classes andsubclasses above and herein.

In certain embodiments, the present invention provides a compound offormula A′ wherein W is C(O) and said compound is of formula A′-1:

wherein each variable is as defined above and described in classes andsubclasses above and herein.

As defined generally above, the A group of formulae A and A′ is a C₁₋₆aliphatic group, wherein A is optionally substituted with Q¹. In certainembodiments, the A group of formulae A and A′ is a C₂₋₅ aliphatic group,wherein A is substituted with one or more Q¹ groups.

As defined generally above, each Q¹ group of formulae A and A′ isindependently selected from cyano, halo, azido, oxo, OR, SR, SO₂R,OSO₂R, N(R)₂, NR(CO)R, NR(CO)(CO)R, NR(CO)N(R)₂, NR(CO)OR, (CO)OR,O(CO)R, (CO)N(R)₂, O(CO)N(R)₂, or OPG¹, wherein PG¹ is a suitablehydroxyl protecting group. In certain embodiments, each Q¹ group offormulae A and A′ is independently selected from cyano, halo, azido,oxo, N(R)₂, OR, SR, SO₂R, or OSO₂R. In other embodiments, each Q¹ groupof formulae A and A′ is independently selected from cyano, halo, azido,oxo, OR, SR, SO₂R, OSO₂R, N(R)₂, NR(CO)R, NR(CO)R, and O(CO)N(R)₂. Instill other embodiments, exemplary Q¹ groups includeNH(CO)(CO)-(heterocyclic radical or heteroaryl), OSO₂-(aryl orsubstituted aryl), O(CO)NH-(aryl or substituted aryl), aminoalkyl,hydroxyalkyl, NH(CO)(CO)-(aryl or substituted aryl),NH(CO)(alkyl)(heteroaryl or heterocyclic radical), O (substituted orunsubstituted alkyl)(substituted or unsubstituted aryl), andNH(CO)(alkyl)(aryl or substituted aryl).

In certain embodiments, the A group of formulae A and A′ has one of thefollowing characteristics:

-   -   (1) A has at least one substituent selected from hydroxyl,        amino, azido, halo, and oxo;    -   (2) A is a C₁₋₆ alkyl group having at least one substituent        selected from hydroxyl, amino, and azido;    -   (3) A has at least two substituents independently selected from        hydroxyl, amino, and azido;    -   (4) A has at least two substituents independently selected from        hydroxyl and amino;    -   (5) A has at least one hydroxyl substituent and at least one        amino substituent;    -   (6) A has at least two hydroxyl substituents;    -   (7) A is a C₂₄ aliphatic group that is substituted;    -   (8) A is a C₃ aliphatic group that is substituted;    -   (9) A has an (S)-hydroxyl alpha to the carbon atom linking A to        the ring containing G or an (R)-hydroxyl; and    -   (10) A is a C₁₋₆ saturated aliphatic group having at least one        substituent selected from hydroxyl and cyano.

The term “(S)-hydroxyl” means that the configuration of the carbon atomhaving the hydroxyl group is (S). Embodiments of the invention alsoinclude compounds wherein A is substituted at least once on each carbonatom: (1) alpha and gamma, (2) beta and gamma, or (3) alpha and beta tothe carbon atom to which A is attached. Each of the alpha, beta, andgamma carbon atoms are independently in the (R) or (S) configuration. Incertain embodiments, the invention provides said compound wherein A issubstituted at least once on each carbon atom alpha and beta to thecarbon atom to which A is attached.

Exemplary A groups of formulae A and A′ include 2,3-dihydroxypropyl,2-hydroxyethyl, 3-hydroxy-4-perfluorobutyl, 2,4,5-trihydroxypentyl,3-amino-2-hydroxypropyl, 1,2-dihydroxyethyl,2,3-dihydroxy-4-perfluorobutyl, 3-cyano-2-hydroxypropyl,2-amino-1-hydroxy ethyl, 3-azido-2-hydroxypropyl,3,3-difluoro-2,4-dihydroxybutyl, 2,4-dihydroxybutyl,2-hydroxy-2-(p-fluorophenyl)-ethyl, —CH₂(CO)(substituted orunsubstituted aryl), —CH₂(CO)(alkyl or substituted alkyl, such ashaloalkyl or hydroxyalkyl) and 3,3-difluoro-2-hydroxypent-4-enyl.

In certain embodiments, the A group of either of formulae A and A′ is3-amino-2-hydroxypropyl.

According to one aspect, the present invention provides a compound ofeither of formulae A and A′, wherein Q¹ is OPG¹, wherein PG¹ is asuitable hydroxyl protecting group. Suitable hydroxyl protecting groupsare well known in the art and include those described in detail inProtecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts,3^(rd) edition, John Wiley & Sons, 1999, the entirety of which isincorporated herein by reference. In certain embodiments, the PG¹ moietyof either of formulae A and A′, taken with the oxygen atom to which itis bound, is selected from esters, ethers, silyl ethers, alkyl ethers,arylalkyl ethers, and alkoxyalkyl ethers. Examples of such estersinclude formates, acetates, carbonates, and sulfonates. Specificexamples include formate, benzoyl formate, chloroacetate,trifluoroacetate, methoxyacetate, triphenylmethoxyacetate,p-chlorophenoxyacetate, 3-phenylpropionate, 4-oxopentanoate,4,4-(ethylenedithio)pentanoate, pivaloate (trimethylacetyl), crotonate,4-methoxy-crotonate, benzoate, p-benzylbenzoate,2,4,6-trimethylbenzoate, carbonates such as methyl, 9-fluorenylmethyl,ethyl, 2,2,2-trichloroethyl, 2-(trimethylsilyl)ethyl,2-(phenylsulfonyl)ethyl, vinyl, allyl, and p-nitrobenzyl. Examples ofsuch silyl ethers include trimethylsilyl, triethylsilyl,t-butyldimethylsilyl, t-butyldiphenylsilyl, triisopropylsilyl, and othertrialkylsilyl ethers. Alkyl ethers include methyl, benzyl,p-methoxybenzyl, 3,4-dimethoxybenzyl, trityl, t-butyl, allyl, andallyloxycarbonyl ethers or derivatives. Alkoxyalkyl ethers includeacetals such as methoxymethyl, methylthiomethyl,(2-methoxyethoxy)methyl, benzyloxymethyl,beta-(trimethylsilyl)ethoxymethyl, and tetrahydropyranyl ethers.Examples of arylalkyl ethers include benzyl, p-methoxybenzyl (MPM),3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl,2,6-dichlorobenzyl, p-cyanobenzyl, 2- and 4-picolyl.

In certain embodiments, the PG¹ moiety of either of formulae A and A′,taken with the oxygen atom to which it is bound, is a silyl ether orarylalkyl ether. In yet other embodiments, the PG¹ moiety of either offormulae A and A′ is t-butyldimethylsilyl or benzoyl. In still otherembodiments, the PG¹ moiety of either of formulae A and A′ ist-butyldimethylsilyl (“TBS”).

As defined generally above, two Q¹ on A are optionally taken together toform a 3-8 membered saturated, partially unsaturated, or aryl ringhaving 0-4 heteroatoms independently selected from nitrogen, oxygen, orsulfur. In certain embodiments, two Q¹ on A are taken together to forman epoxide ring.

In certain embodiments, the PG⁵ and PG⁶ groups of formula A and A′ areindependently selected from those suitable protecting groups describedabove for the PG¹ group of formula A and A′. In other embodiments, thePG⁵ and PG⁶ groups of formula A and A′ are taken together to form acyclic diol protecting group. Such diol protecting groups are well knownin the art and include those described by Greene and includecyclohexylidene and benzylidene diol protecting groups.

In certain embodiments, the present invention provides a method forpreparing compounds of formula F-2 according to Schemes V-a, V-b, andV-c below:

In other embodiments, the present invention provides crystallineER-817664.

Using ER-817664 as a crystalline intermediate, Scheme VI-a shows ageneral method for using this compound in the preparation ofintermediates useful for preparing compounds of formula F-2.

The triol intermediate depicted in Scheme VI-a above is used in analternate method for preparing intermediates useful for preparingcompounds of formula F-2, as shown in Scheme VI-b below.

In Scheme VI-b, shown above, the triol intermediate is treated withperiodate to form the aldehyde. This compound is homologated with methylWittig reagent, and the resulting olefin reduced, to form the estercompound. The remaining free hydroxyl group is treated withN-iodosuccinimide to form the iodo intermediate and the ester reducedwith sodium borohydride to form the hydroxyl compound depicted above.One of ordinary skill in the art will recognize that the resulting iodocompound corresponds to compound 21 depicted in Scheme II, supra,wherein compound 21 has a protecting group at the hydroxyl position. Thefinal treatment with zinc affords the lactone depicted above. One ofordinary skill in the art will recognize that the resulting lactonecompound corresponds to compound 22 depicted in Scheme II, supra,wherein compound 22 has a protecting group at the hydroxyl position.

Yet another alternate method for preparing intermediates useful forpreparing compounds of formula F-2 from D-quinic acid provides analternative route from intermediate 2, of Scheme II as shown in SchemeVII below.

In Scheme VII above, intermediate 2 (from Scheme II) is used to prepareER-812829 in a stereoselective manner. It will be appreciated that otherprotecting groups are useful for protecting the diol of ER-812829. Suchgroups are known to one of ordinary skill in the art and includecyclohexylidene and benzylidene diol protecting groups. First, at step(a), the hydroxyl group of ER-811510 is treated with 2-bromoacetylchloride to form ER-812771. The bromo intermediate is treated withtriphenylphosphine to form a Wittig reagent in situ in a mannersubstantially similar to that described by Murphy, et al, TetrahedronLetters, 40, (1999) 3455-3456. This Wittig reagent then forms thelactone ER-812772. At step (d), stereoselective hydrogenation of thedouble bond affords ER-812829.

The present invention also provides a method for preparing intermediatesuseful for preparing compounds of formula F-2 from D-quinic acid, fromintermediate ER-812829 depicted in Scheme VII above, as shown in SchemeVII-a below.

3. Fragment F-3

According to yet another embodiment, the present invention provides acompound

wherein:each PG⁴ is an independently selected suitable hydroxyl protectinggroup;R³ is CHO or C(O)OR⁴;R⁴ is a suitable carboxyl protecting group; andLG² is a suitable leaving group.

Suitable carboxylate protecting groups are well known in the art and aredescribed in detail in Protecting Groups in Organic Synthesis, T. W.Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999. Incertain embodiments, the R⁴ group of F-3 is an optionally substitutedC₁₋₆ aliphatic group or an optionally substituted aryl group. Examplesof suitable R⁴ groups include methyl, ethyl, propyl, isopropyl, butyl,isobutyl, benzyl, and phenyl wherein each group is optionallysubstituted.

As described above, suitable leaving groups are well known in the art,e.g., see “Advanced Organic Chemistry,” Jerry March, 4^(th) Ed., pp.351-357, John Wiley and Sons, N.Y. (1992). Such leaving groups include,but are not limited to, halogen, alkoxy, sulphonyloxy, optionallysubstituted alkylsulphonyloxy, optionally substitutedalkenylsulfonyloxy, optionally substituted arylsulfonyloxy, silyl, anddiazonium moieties. Examples of suitable leaving groups include chloro,iodo, bromo, fluoro, methanesulfonyloxy (mesyloxy), tosyloxy, triflate,nitro-phenylsulfonyloxy (nosyloxy), and bromo-phenylsulfonyloxy(brosyloxy). In certain embodiments, the LG² moiety of F-3 is iodo.

According to an alternate embodiment, the suitable leaving group may begenerated in situ within the reaction medium. For example, LG² in acompound of formula F-3 may be generated in situ from a precursor ofthat compound of formula F-3 wherein said precursor contains a groupreadily replaced by LG² in situ. In a specific illustration of such areplacement, said precursor of a compound of formula F-3 contains agroup (for example, a trimethylsilyl group) which is replaced in situ byLG², such as an iodo group. The source of the iodo group may be, e.g.,N-iodosuccinimide. Such an in situ generation of a suitable leavinggroup is well known in the art, e.g., see Id.

As described above, suitable hydroxyl protecting groups are well knownin the art and include those described in detail in Protecting Groups inOrganic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, JohnWiley & Sons, 1999 the entirety of which is incorporated herein byreference. In certain embodiments, each PG⁴, taken with the oxygen atomto which it is bound, is independently selected from esters, ethers,silyl ethers, alkyl ethers, arylalkyl ethers, and alkoxyalkyl ethers.Examples of such esters include formates, acetates, carbonates, andsulfonates. Specific examples include formate, benzoyl formate,chloroacetate, trifluoroacetate, methoxyacetate,triphenylmethoxyacetate, p-chlorophenoxyacetate, 3-phenylpropionate,4-oxopentanoate, 4,4-(ethylenedithio)pentanoate, pivaloate(trimethylacetyl), crotonate, 4-methoxy-crotonate, benzoate,p-benzylbenzoate, 2,4,6-trimethylbenzoate, carbonates such as methyl,9-fluorenylmethyl, ethyl, 2,2,2-trichloroethyl, 2-(trimethylsilyl)ethyl,2-(phenylsulfonyl)ethyl, vinyl, allyl, and p-nitrobenzyl. Examples ofsuch silyl ethers include trimethylsilyl, triethylsilyl,t-butyldimethylsilyl, t-butyldiphenylsilyl, triisopropylsilyl, and othertrialkylsilyl ethers. Alkyl ethers include methyl, benzyl,p-methoxybenzyl, 3,4-dimethoxybenzyl, trityl, t-butyl, allyl, andallyloxycarbonyl ethers or derivatives. Alkoxyalkyl ethers includeacetals such as methoxymethyl, methylthiomethyl,(2-methoxyethoxy)methyl, benzyloxymethyl,beta-(trimethylsilyl)ethoxymethyl, and tetrahydropyranyl ethers.Examples of arylalkyl ethers include benzyl, p-methoxybenzyl (MPM),3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl,2,6-dichlorobenzyl, p-cyanobenzyl, 2- and 4-picolyl.

In certain embodiments, one, two, or three of the PG⁴ moieties of F-3,taken with the oxygen atom(s) to which they are bound, are silyl ethersor arylalkyl ethers. In yet other embodiments, one, two, or three of thePG⁴ moieties of F-3 are t-butyldimethylsilyl or benzyl. In still otherembodiments, all three of the PG⁴ moieties of F-3 aret-butyldimethylsilyl.

According to another embodiment, a compound of formula F-3 is providedwherein said compound has the stereochemistry as depicted in formulaF-3′:

wherein each variable is as defined above and described in classes andsubclasses above and herein.

In certain embodiments, a compound F-3a is provided:

wherein “TBS” refers to t-butyldimethylsilyl.

Details of the synthesis of F-3a are set forth in the Examples infra.

4. Assembly of F-1, F-2, and F-3 to Prepare Compound I

Coupling of the fragments F-1 and F-2 is accomplished, in general, asset forth in Scheme VIII below.

Scheme VIII above shows a general method for preparing intermediate F-5afrom fragments F-1 and F-2. First, fragments F-1 and F-2 are coupledusing methods substantially similar to that described by Kishi, et al.,Org Lett 4:25 p 4431 (2002) to afford intermediate F-4. This coupling isperformed in the presence of the chiral oxazole (ER-807363) or,alternatively, in the absence of ER-807363. However, the couplingreaction of F-1 and F-2 proceeds with higher selectivity when performedin the presence of ER-807363. Intramolecular Williamson ether formationof F-4, by treating F-4 with potassium hexamethyldisilazide, thenfurnishes tetrahydropyran F-5 as a mixture of stereoisomers. Thestereoisomers are then separated to afford F-5a. The details of thesesteps are set forth in the Examples infra.

According to another embodiment, the present invention provides acompound F-4:

wherein PG¹, PG², PG³, LG¹, and R¹ are as defined in general and insubclasses above and herein.

In certain embodiments, the present invention provides a compound offormula F-4 wherein said compound has the stereochemistry depicted informula F-4′:

wherein PG¹, PG², PG³, LG¹, and R¹ are as defined in general and insubclasses above and herein.

The present invention also provides a compound F-4-a:

wherein “MsO” refers to mesylate, “TBS” refers to t-butyldimethylsilyl,and “OPv” refers to pivaloate.

Details of the synthesis of F-4a are set forth in the Examples infra.

According to yet another embodiment, the present invention provides acompound F-5:

wherein each PG¹, PG², PG³, and R¹ is as defined in general and insubclasses above and herein.

In certain embodiments, the present invention provides a compound offormula F-5 having the stereochemistry as depicted in formula F-5′ orF-5a:

wherein each PG¹, PG², PG³, and R¹ is as defined in general and insubclasses above and herein.

The PG³ group of intermediate F-5a is removed and the resulting hydroxylcompound F-6 is then coupled with a compound F-3′, wherein R³ is CHO, toform F-7 as depicted in Scheme IX below.

Scheme IX above shows a general method for preparing an intermediate F-9from F-3′ and F-6. First, the sulfone intermediate F-6 is treated withn-butyl lithium then with the aldehyde F-3′. The resulting diolintermediate F-7 is then oxidized with Dess-Martin reagent to form theketone-aldehyde intermediate F-8 which is then treated with SmI₂ toafford intermediate F-9. The details of these steps are set forth in theExamples infra.

Scheme X above sets forth a general method for preparing theHalichondrin B analogs of the present invention from F-9a (LG² is iodo).First, an intramolecular coupling is achieved, by conditionssubstantially similar to those described at Scheme V above, to formhydroxyl compound F-10. In an alternate method, the intramolecularcoupling is performed in the presence of the chiral oxazole ligand,described herein. The addition of the chiral oxazole ligand imparts ahigher yield and greater efficiency for the reaction. The details ofthis reaction are set forth in the Examples below. Compound F-10 is thenoxidized to form F-11. The hydroxyl protecting groups of F-11 areremoved by appropriate means to afford F-12. One of ordinary skill inthe art would recognize that the methods appropriate to achieve removalof the protecting groups of compound F-11 depend upon the actualprotecting groups used and include those described by Greene. Forexample, when each of the hydroxyl protecting groups of F-11 is a TBSgroup, such removal may be achieved by treatment with optionallybuffered tetrabutylammonium fluoride. The details of these steps are setforth in the Examples infra.

Intermediate F-12 is useful for preparing various analogs ofHalichondrin B as described in, e.g. U.S. Pat. No. 6,365,759 and U.S.Pat. No. 6,469,182 the entirety of which are incorporated herein byreference.

EXAMPLES

Using the preparation of Halichondrin B analog B-1939 to exemplify, thefollowing Examples describe the synthesis of Halichondrin B analogsusing the methods and compounds of the present invention.

One of ordinary skill in the art would recognize that many analogs ofHalichondrin B are prepared by the methods and from the compounds of thepresent invention including, but not limited to, those analogs ofHalichondrin B described in U.S. Pat. Nos. 6,214,865 and 6,365,759, theentirety of which are herein incorporated by reference. Accordingly, itwill be appreciated that the synthetic methods described below, by wayof example, do not limit the scope of the invention which is defined bythe appended claims.

Example 1 Preparation of F-1a

In an appropriately sized vessel, D-glucurono-6,3-lactone (1 wt., 1 eq.)was combined with ACN (3 vol.) and acetone (9 vol.). Catalytic conc.sulfuric acid was added and the system held at reflux for 3 hours. Thesystem was checked for dissolution of D-glucurono-6,3-lactone. Thereaction was cooled to 25° C. and stirred for 15 hours. Solid sodiumbicarbonate (0.5 wts) was added and the reaction stirred for 3additional hours. Solids were removed by filtration and the organicswere partially concentrated and azeotroped with additional ACN (2 wts).ER-806045 was taken into the next reaction without isolation.

Crude ER-806045 (1 wt, 1 eq.) was dissolved in ACN (6.5 vol.) at −20° C.Pyridine (1.5 vol., 4.0 eq.) was added and SO₂Cl₂ (0.38 vol., 1.02 eq.)was added slowly, while keeping the internal temperature below 5° C. Thereaction was quenched by inverse addition into cool water (28 vol.) withan ACN rinse (0.5 vol.), keeping the internal temperature below 10° C.The white solid, ER-806410 (0.87 wt., 79% of theoretical) was isolatedby filtration with a heptane rinse (2 vol.) and drying.

An appropriately sized vessel was charged with ER-806410 (1 wt, 1 eq.)and THF (10 vol.) and then cooled to 10° C. Wet palladium on carbon (5%,0.5 wts) was added and the heterogeneous solution stirred for tenminutes. The reaction was buffered with pyridine (0.44 wts, 1.3 eq.) andplaced under a hydrogen atmosphere for 3 hours. The reaction wasfiltered and the solids rinsed with water (2 vol.) and EtOAc (10 vol.).The resulting solution was acidified with 1N HCl (2.1 vol.), mixed welland the resulting layers were separated. The organic layer wassequentially washed with aqueous sodium bicarbonate (5 vol.) and water(5 vol.). The organics were concentrated under reduced pressure and theresulting product recrystallized from IPA (3.4 vol.) and further croppedby the addition of heptane (3.4 vol.) at 15° C. ER-806047 was isolatedas a white solid (67% yield).

An appropriately sized vessel was charged with ER-806047 (1 wt, 1 eq.)and toluene (8 vol.) and then cooled to −40° C. A 17 wt % solution ofDIBAL in toluene (4.6 wts, 1.1 eq.) was added, keeping the internaltemperature below −35° C. After assaying the reaction, excess reagentwas quenched by the addition of acetone (0.15 wts, 0.5 eq.), keeping thetemperature below 10° C. The reaction was diluted with EtOAc (7 vol.)and 15% aqueous citric acid (8 wts) below 10° C., and stirred at 20° C.until a clear solution was obtained. The layers were separated and theaqueous layer back extracted twice with EtOAc (2×10 vol.). The combinedorganics were washed sequentially with aqueous sodium bicarbonate (5vol.) and brine (5 vol.) and then dried with magnesium sulfate (0.2wts). After filtration, the organic layers were partially concentratedat reduced pressure, and azeotroped with toluene (4 vol.). The productswere stored as a THF solution for use in the next reaction.

An appropriately sized vessel was charged with a 20 wt % ether solutionof TMSCH₂MgCl (2.04 wts, 3.0 eq.) and chilled below 5° C. A THF (7 vol.)solution of ER-806048 (1 wt, 1 eq.) was added to the reaction vesselkeeping the internal temperature below 15° C. The reaction was warmed to35° C. for 1.5 hours. The reaction was cooled, diluted with toluene (7vol.) and quenched with AcOH (3 vol.) below 20° C. The reaction wasfurther diluted with 10% aqueous ammonium chloride (6 wts), mixed well,and the layers were separated. The organic layer was washed sequentiallywith aqueous sodium bicarbonate (5 vol.) and brine (5 vol.). Afterdrying over magnesium sulfate (0.2 wts) and filtration, the solution wasconcentrated under reduced pressure and ER-807114 isolated as aconcentrated solution in toluene (90% yield).

An appropriately sized vessel was charged sequentially with ER-807114 (1wt, 1 eq.) and THF (20 vol.), and the solution was cooled below 5° C. A15 wt % solution of KHMDS in toluene (9.16 wts, 2.0 eq.) was added. Thereaction was quenched with 10% aqueous ammonium chloride (5 vol.). Thelayers were separated and the organic layer washed sequentially withammonium chloride (5 vol.), 2N HCl (8.5 vol.), aqueous sodiumbicarbonate (5 vol.), and water (5 vol.). The organics were transferredto concentration vessels using EtOAc, and concentrated to a viscous oil(90% yield). The material was recrystallized from toluene (4 vol.) andheptane (4 vol.) at 35° C. with additional cropping at lowertemperatures and heptane (2×4 vol.) at 15 and 10° C. (94% yield).

An appropriately sized vessel was charged with KOtBu (0.67 wts, 1.2 eq.)and THF (7.7 vol.), and cooled to an internal temperature of −20° C. Asolution of ER-806049 (1 wt, 1 eq.) in THF (2.3 vol.) was added keepingthe internal temperature below −7° C. Neat BnBr was added, maintaining−7° C. as the maximum temperature. The reaction was stirred at −20° C.for 2 hours and 10 hours at 10° C. The reaction was quenched with 10%aqueous NH₄Cl (4 wts), diluted with toluene (4 vol.), and mixed well.The layers were separated and the organic layer washed with 10% brine (4wts) and dried over MgSO₄ (0.15 wts). ER-806050 was isolated as a tBuOHsolution (2.5 vol.) after concentration at reduced pressure (95% yield).

An appropriately sized vessel was charged sequentially with K₃Fe(CN)₆(3.5 wt., 3.4 eq.), K₂CO₃ (1.5 wt., 3.4 eq.), (DHQ)₂AQN (0.0134 wt.,0.005 eq.), water (18 vol.), t-BuOH (13 vol.), and ER-806050 in tBuOH (1wt, 1 eq. in 5 vol.). The heterogeneous mixture was cooled to aninternal temperature of 0° C., and K₂OsO₄.2H₂O (0.0029 wt., 0.22 mole %)was added. After 36 hours at 0° C., the reaction was quenched withNa₂S₂O₃ (3.5 eq., 1.7 wt.) and the flask allowed to warm to ambienttemperature overnight. After 15 hours, the mixture was transferred to aworkup vessel and diluted with toluene (15 vol.) and water (4 vol.). Thebiphasic mixture was vigorously stirred and separated. The organic layerwas washed with brine (10 vol.), and concentrated and solvent exchangedto afford a crude mixture of diols ER-806051 and ER-806052 as a 10%toluene solution (92% yield).

The toluene solution (10.1 wt %, 9.9 wts) of ER-806051/52 (1 wt, 1 eq.)was further diluted with additional toluene (3 wts). N-Methylmorpholine(0.94 wts, 3.0 eq.) and DMAP (0.075 wts, 0.2 eq.) were added to thetoluene solution and the resulting mixture was cooled below 15° C.Benzoyl chloride was added keeping the internal temperature below 25° C.The reaction was then stirred for 12 hours at 75° C. The reaction wascooled to 15° C. and the temperature kept below 25° C. during the 1N HCl(5 vol.) quench. Layers were mixed well and separated. The organic layerwas sequentially washed with brine (3 wts), aqueous sodium bicarbonate(3 wts), and brine (3 wts). The organic layer was dried (MgSO₄, 0.25wts), treated with activated carbon (0.1 wts), and filtered (Celite®,0.3 wts) with toluene (1 wt). The products were partially concentratedunder reduced pressure, azeotroped with toluene (3 wts). BisbenzoateER-806053/54 was isolated in 95% yield as a toluene solution (5 vol.).

Under an inert atmosphere, a 20 wt % solution of TiCl₄ (6.42 wts, 3.6eq.) in toluene was cooled to 15° C. Keeping the internal temperaturebelow 30° C., Ti (OiPr)₄ (0.64 wts, 1.2 eq.) was added, and theresulting solution stirred for 15 minutes. AllylTMS (1.03 wts, 4.8 eq.)was premixed with ER-806053/54 (1 wt, 1 eq.), available as a 22 wt %solution in toluene from the previous step (4.55 wts, 1 eq.), and addedto the freshly generated Ti (OiPr)Cl₃. The internal temperature duringthe addition was kept below 30° C. The reaction was stirred between20-30° C. for 2 hours. The reaction was cooled to −5° C. and quenchedwith 1N HCl (6 vol.), keeping the internal temperature below 30° C.After mixing well, the layers were separated and the organic layersequentially washed with 1N HCl (3 vol.) and brine (2×3 vol.). Theorganic layer was stirred with MgSO₄ (0.3 wts) and activated carbon(0.15 wts) and filtered through a Celite® plug (0.2 wts), rinsing withtoluene (1 vol.). The product, as a 3:1 mixture at C-34 was isolatedafter concentration in 83% yield. Recrystallization from IPA/n-heptaneafforded ER-806055 with >99.5% d.e. at C-34 (71% yield).

At room temperature, an appropriately sized vessel was charged withalcohol ER-806055 (1 wt., 1.0 eq.), toluene (7 vol.), DMSO (0.31 wt.,2.0 eq.) and Et₃N (0.78 wt., 4.0 eq.). The resulting solution was cooledto −19° C. TCAA (0.84 wt., 1.4 eq.) was added drop-wise, keeping theinternal temperature below −10° C. The reaction was stirred for anadditional 10 minutes. The reaction was diluted with IPA (0.5 vol.) andquenched with 1N HCl (5 vol.), keeping the internal temperature below10° C. The layers were separated and the organic layer sequentiallywashed with aqueous NaHCO₃ (5 wt.) and water (3 vol.). The organic layerwas partially concentrated at reduced pressure (100% crude yield) andfurther azeotroped with additional toluene (4 vol.). The resultingketone (ER-806058) was dissolved in a final 4 vol. of toluene, checkedfor water content and used as is in the next reaction.

A solution of ER-107446 (1 wt, 1.5 eq.) in THF (2.7 vol.) was cooled to10° C. and treated with 25.5 wt % LHMDS in THF (5.2 wt., 1.4 eq.),keeping the internal temperature below 15° C. In a second vessel, thetoluene solution of crude ER-806058 (21.9 wt %, 5.4 vol.) was cooled to10° C. The contents of vessel one were transferred into the substratecontaining solution, keeping the internal temperature below 20° C. Thereaction was stirred for 30 minutes then quenched by adding 1M HCl (6.5vol.), keeping the internal temperature below 20° C. The layers wereseparated and the organic layer washed four times with 1:1 MeOH/water(4×5 vol.) and then with aqueous bicarbonate (5 vol.), and brinesolutions (2×5 vol.). The product was dried over MgSO₄ (0.52 wt.),filtered (rinsing with 0.7 vol. of toluene), and concentrated to a heavyoil at reduced pressure.

ER-806059 was dissolved in 1:1 toluene/CH₃CN (5 vol.) at roomtemperature. Filtered TMSI (1.23 wt., 4 eq.) was added, keeping theinitial temperature below 40° C. The reaction was heated to 60° C. for 2hours. The reaction was cooled to −15° and quenched with 25% aqueousammonium hydroxide below 30° C. The reaction contents were stirredovernight and the layers separated. The organic layer was charged withadditional toluene (5 vol.) and water (2 vol.). The layers were mixedwell and separated. The organic layer was then washed sequentially with10% aqueous sodium sulfite (5 vol.), 1N HCl (5 vol.), 5% aqueous sodiumbicarbonate (5 vol.), and brine (5 vol.). The organic layer was driedover MgSO₄ (0.2 wt.), filtered, partially concentrated and used in thenext reaction as a 50% solution in toluene.

In an appropriately sized vessel, NaBH(OAc)₃ (1.19 wt, 3.15 eq.), Bu₄NCl(1.04.wt, 2.1 eq.), DME (8.2 vol.), and toluene (4 vol.) at 65° C., werecombined and stirred at room temperature. The mixture was heated to 75°C. for one hour. ER-806060 (1 wt., 1 eq.) as a 50% wt solution intoluene was added at 75° C. and rinsed in with additional toluene (0.3vol.). The reaction temperature was raised to 85° C. and the reactionstirred for 2-4 hours. The reaction was cooled to <10° C. and quenchedwith water (3.2 vol.) keeping the internal temperature below 20° C. Thelayers were mixed well and separated. The organic layer was sequentiallywashed with aqueous sodium bicarbonate (2×5 vol.) and water (2×5 vol.).The organic layer was concentrated and solvent exchanged to afford a 40wt % solution of ER-806061 in MeOH.

A 40 wt % solution of ER-806061 (1 wt., 1.0 eq.) in MeOH was dissolvedin additional methanol (1.6 vol.). Potassium carbonate (0.24 wts, 1.0eq.) was added and the reaction temperature was raised to 50° C. for onehour. The reaction was cooled to 15° C., and quenched with 1N HCl (3.5vol., 2 eq.) with the internal temperature below 30° C. The reaction wasdiluted with water (3.9 vol.) and toluene (3 vol.). The layers wereseparated and the aqueous layer back extracted with toluene (1.5 vol.).The aqueous phase was charged with sodium bicarbonate (0.3 wts) andsodium chloride (0.6 wts), and back extracted with nBuOH (3 vol.). Thethree organic phases were combined and concentrated to dryness to affordcrude triol ER-806064 and inorganic salts. The product was dissolved in7:1 toluene/nBuOH at 80° C., hot filtered, and recrystallized by coolingand stirring overnight. ER-806064 (F-1b) was isolated in a 57%, fivestep overall yield after filtration and a toluene rinse. FAB(+)-MS m/z357 (M+H). Melting point 96.2° C.

Purified triol ER-806064 (1 wt., 1 eq.) was dispersed in acetone (2vol.), diluted with 2,2-dimethoxypropane (1 vol.), and treated withconc. sulfuric acid (0.0086 wts, 0.03 eq.) at 25° C. The reaction wasstirred until homogenous. The reaction was diluted with toluene (5 vol.)and quenched by the addition to 5% K₂CO₃ (2 vol.). The layers were mixedwell and separated. The organic layer was washed with 10% brine, driedwith Na₂SO₄ (0.5 wt.). The solution was filtered (toluene rinse) andconcentrated at reduced pressure to afford ER-806126 as a yellow oil.The material was used as is in the next stage.

Solid NaOtBu (0.34 wt., 1.4 eq.) was dissolved in THF (2.7 vol.) and DMF(0.3 vol.), and then cooled below 10° C. A solution of ER-806126 (1 wt.,1 eq.) in THF (2.5 vol.) was added to the NaOtBu solution with a THFrinse (0.5 vol.), keeping the internal temperature below 15° C. After a30 minute stir, methyl iodide (0.204 vol., 1.3 eq.) was added keepingthe temperature below 15° C. (exothermic). The reaction was warmed to25° C. and the reaction quenched with water (5 vol.) and diluted withtoluene (7 vol.). The layers were mixed well and separated. The organiclayer was washed twice with brine (2×5 vol.), dried over Na₂SO₄ (0.5wt.), filtered, and concentrated under reduced pressure.

ER-806068 (1 wt., 1 eq.) was dissolved in 1 vol. of MeOH. Water (1.5vol.) and 2 N HCl (1.25 vol., 1 eq.) were added and the reaction stirredat 25° C. The reaction was quenched by inverse addition to 2M NaOH (1.34vol.) at 10° C. The reaction was diluted with isopropyl acetate (5vol.), the layers were mixed well and separated. The aqueous layer wasback extracted with 5 vol. of isopropyl acetate and the combined organiclayers were dried over Mg SO₄ (0.5 wt.), filtered, and concentrated atreduced pressure to afford crude diol ER-806063.

To a 25° C. solution of crude ER-806063 (1 wt., 1.0 eq.) in DMF (4vol.), was charged imidazole (0.62 wt., 3.4 eq.), followed by TBSCl(1.02 wt., 2.53 eq.) with the internal temperature below 30° C. Thereaction was stirred at 25° C. The reaction was diluted with MTBE (10vol.) and washed with H₂O (4 vol.). The organic layer was washedsequentially with 1M HCl (3 vol.), water (3 vol.), aqueous sodiumbicarbonate (3 vol.), and brine (3 vol.). The organic layer was driedover MgSO₄ (0.5 wt.), filtered with one volume MTBE rinse, andconcentrated at reduced pressure and solvent exchanged for heptane (4vol.).

ER-806065 (1 wt., 1 eq.) was dissolved in heptane, isooctane, or IPA (10vol.) The solution was cooled below −60° C. (±10° C.). Ozone was bubbledthrough the solution at low temperature until the solution retained ablue color. Nitrogen was purged through the solution for 15-30 minutes,and the reaction warmed to 5° C. while the nitrogen flush was continued.7-15 wt. % Lindlar Catalyst (5% Pd on CaCO₃ poisoned with Pb, 0.1 wt.)was added. The reactor head was purged several times with nitrogen,evacuated, and placed under 1 atmosphere H₂ (g). The reaction was thenwarmed to room temperature (20-25° C.). The reaction was stirred for 2.5hours. The resulting heterogeneous solution was filtered through Celite®(1.0 wt.) with an MTBE (2 vol.) rinse. The solution was concentrated todryness, isolating 1.0 wt. of crude ER-806067. The crude isolate wasrecrystallized from heptane or isooctane to afford ER-806067 (F-1a) as awhite crystalline solid in a 68% five step yield. FAB(+)-MS m/z 601(M+H). Melting point 64.5° C.

Example 2 Preparation of F-2a

A reactor was charged with pre-rinsed Amberlyst 15 (0.05 wt.) and water(4.63 vol.) and cooled to an internal temperature of 0-5° C. The reactorwas charged with 2,3-dihydrofuran (1 wt., 1 eq.) and stirred for 1.5hours maintaining internal temperature around 5° C. A second reactor wascharged with water (4.63 vol.) and heated to an internal temperature of35° C. The same reactor was charged with tin powder (2.2 wt., 1.3 eq.),distilled 2,3-dibromopropene (3.71 wt., 1.3 eq.), and 48% hydrobromicacid (0.002 vol.), respectively. After observation of reactioninitiation indicated by a temperature spike to 36-38° C., the secondreactor was charged with 2,3-dibromopropene portion-wise (9×0.37 wt.)while maintaining the internal temperature below 45° C. After completeaddition, the contents of the second reactor were stirred at an internaltemperature of 35° C. for an additional 60 minutes. The filteredcontents of the first reactor were charged into the second reactor at arate such that internal temperature did not exceed 45° C. After completeaddition, the heat source was removed and the second reactor was chargedwith Celite® 545 (2.0 wt.) and the resulting mixture stirred for 30minutes. The heterogeneous mixture was filtered through a Celite® 545pad (2.0 wt.) and the cake washed with additional water (5 vol.). Allfiltrates were combined into a reactor and charged with concentratedhydrochloric acid (1.5 vol.) until the cloudy solution becomes clear.With vigorous stifling, the reactor was charged with sodium chloride(3.6 wt.) and the layers allowed to partition. The organic layer wasseparated and set aside. The aqueous layer was extracted with n-butanol(20 vol.). The aqueous layer was drained and the reactor charged withthe organics from the first separation. The organics were washed withconcentrated sodium bicarbonate (24 vol.), followed by a back extractionof the aqueous layer with n-butanol (20 vol.). All organics werecombined and concentrated in vacuo. The concentrate was dissolved inMTBE (10 vol.), filtered and the filtrate was concentrated to two vol.With stifling, the concentrate was cooled to an internal temperature of0° C. and then n-heptane (4 vol.) was added. The heterogenous mixturewas stirred for 2 hours at an internal temperature of 0° C. and thedesired product was isolated via filtration and dried under vacuum toyield ER-806909 (1.34 wt., 0.45 eq.) as a white powder.

A reactor was charged with imidazole (0.65 wt., 2 eq.), ER-806909 (1wt., 1 eq.), and anhydrous DMF (4.04 vol.). With stifling, the reactorwas cooled to an internal temperature of 0° C. and then withtert-butylchlorodiphenylsilane (1.25 wt., 0.95 eq.) at a rate such thatinternal temperature did not exceed 15° C. While maintaining theinternal temperature<15° C., the reaction was stirred for an additional1 hour. The reactor was charged with water (3.2 vol.) and n-heptane (6.4vol.). The mixture was stirred for 5-15 minutes and the layers allowedto separate. The organic layer was separated and set aside. The aqueouslayer was extracted with n-heptane (3.2 vol.). All organics werecombined and washed with brine (3.2 vol.) and concentrated in vacuo to aconstant weight to yield ER-806545 (2.13 wt., 0.95 eq.) as a yellow oil.The product was utilized in the next stage without further purification.

The enantiomers of ER-806545 were separated via Simulated Moving Bed(SMB) chromatography to yield ER-808373 (0.55 wt., 0.55 eq.) andER-806721 (0.45 wt., 0.45 eq.) as yellow oils. The SMB chromatographyprotocol used to separate the enantiomers of ER-806545 is as follows.

-   -   Columns and media: Chiracel OD 20 μm 30 mm×150 mm (12 columns)    -   Solvent system: 96:4 (vol/vol) heptane:tert-butanol (mobile        phase)    -   Simulated Moving Bed    -   Chromatography apparatus: Knauer SMB System CSEP C912    -   Isotherms (Langmurian, determined by frontal analysis):        -   Undesired isomer: Qi*=2.8768×Ci/(1+0.02327×Ci)        -   Desired isomer: Qi=4.5320×Ci/(1+0.0034595×Ci)    -   *Where Qi=solid phase concentration (in g/L) and Ci=liquid phase        concentration (g/L).    -   Column porosity: 0.658    -   Temperature: 27° C.    -   Flow rates, etc. calculated by simulation on EuroChrom 2000 for        Windows, SMB_Guide ver.1.2, Wissenschaftliche Geratebau Dr.-Ing.        Herbert Knauer GmbH, D-14163 Berlin; authors, H. Kniep and A.        Seidel-Morgenstern:        -   Feed concentration: 36 g/L (ER-806545)        -   Feed flow rate (Pump 1): 15 mL/min        -   Eluent flow rate (Pump 2): 76.4 mL/min        -   Zone IV (Pump 3) flow rate: 107 mL/min        -   Zone II (Pump 4) flow rate: 134.3 mL/min (actual flow            rate=143.5 mL/min)        -   Zone I flow rate: 183.4 mL/min        -   Zone III flow rate: 149.3 mL/min        -   Raffinate*flow rate: 42.3 mL/min*Raffinate=weakly bound            isomer        -   Extract flow rate: 49.1 mL·min*Extract=strongly bound isomer        -   Tact time        -   (port switching time): 0.8864 min (53.18 sec, actual tact            time=54 sec)

The enantiomers of ER-806545 were separated using the above protocol inthe following manner. For an 11 hour run, 10 L of 36 g/L ER-806545 inmobile phase was pumped (Silog model Chemtech) through a 142 mm diameter0.45 μm pore size nylon filter (Cole-Parmer #2916-48) and into the Feedtank. The Eluant tank was filled with 36 L mobile phase that has beenfiltered through an in-line 45 mm diameter 1 μm glass fiber filter(Whatman GFC), additional vol. were added throughout the run. Theinternal temperature of the SMB apparatus was adjusted to 27° C.

For initial startup, the Feed and Eluant inlets were both connected tothe Eluant tank. The Feed and Eluant pumps were primed and purged withmobile phase solvent. The SMB apparatus column switching was initiated,the pumps were turned on and the flow rates were gradually increased tofull speed while maintaining absolute flow rate differences between eachpump. Once full speed was achieved the Raffinate and Extract flow rateswere measured and adjustments to pump flow rates were made to correctfor deviations in pump specifications. The Feed pump (Pump 1) wasreduced to 0 mL/min, the inlet reconnected to the Feed tank, the pumpprimed with Feed solution and then the flow rate gradually increasedback to full operating speed. The Raffinate and Extract outlets werecollected into separate tanks and samples of each were acquired every 2hours. The samples were monitored for chiral purity by analytical HPLCusing the HPLC method set forth below. Adjustments to the flow rates ofPumps 2, 3 and 4 as well as to the tact time were made to afford thedesired outlet purities.

At the end of the run, the Feed pump was once again reduced to zero flowrate and connected to the Eluant tank. The Feed pump was brought back tofull speed and the system was allowed to wash for 20 minutes. TheRaffinate and Extract outlets were maintained for 10 minutes (10 tacts)during the wash period and, for the remainder of the wash, the outletswere collected into a separate tank. The column wash was eventuallyconcentrated and added to the Feed on subsequent runs.

The collected Extract (ER-806721) at the end of each run was pooled withmaterial collected from the same starting material lot and the finalpooled lot was analyzed again for chiral purity by the analytical HPLCmethod described in Table 1 below. The same procedure was applied to thecollected Raffinate (ER-808373).

TABLE 1 HPLC Analysis of ER-806721 chiral purity: Column: Chiracel OD 10um 250 × 4.6 mm, DAICEL Chemical Industries, Ltd., cat. no. 14025 Flowrate: 0.8 mL/min Temp. (° C.): 27 preferred over 35 Inj. Vol.: 10 uLusually, sample in Solvent A, 5 mg/mL Instrument: Waters Alliance W2690with UV W2487 (also with Advanced Laser Polarimeter) Mobile PhaseConstituents: (PDR-Chiral, Inc.) A 99:1 Heptane:2-Propanol B C DGradient Table: (%) Time (min) A B C D Gradient 0 100 0 0 0 isocraticRun time 30 min Detection: Absorbance at 254 nm UV

A reactor was charged with triphenylphosphine (0.7 wt., 1.2 eq.),p-nitrobenzoic acid (0.45 wt., 1.2 eq.), ER-808373 (1 wt., 1 eq.), andanhydrous toluene (8 vol.). The reaction was cooled to internaltemperature of 0° C. and DEAD (1.17 wt., 1.2 eq.) was slowly added at arate such that the internal temperature did not exceed 7° C. n-Heptane(3.3 vol.) was added and the mixture cooled to an internal temperature10° C. then stirred for 30-40 minutes. The resulting precipitate wasremoved by filtration. The filter-cake was washed with n-heptane (3.3vol.), TBME (0.55 vol.), n-heptane (1.1 vol.), and MTBE (0.55 vol.),respectively. All filtrates were combined and concentrated in vacuo. Thecrude concentrate was dissolved in THF (8 vol.) then water (0.8 vol.)and lithium hydroxide dihydrate (0.18 wt., 2 eq.) were added. Themixture was stirred at ambient temperature then n-heptane (3.3 vol.) wasadded and stirred for 5 minutes. Water (2.2 vol.) and n-heptane (3.3vol.) were added, the biphasic mixture was stirred for 5 minutes, andthe layers were allowed to partition. The aqueous layer was separatedand back extracted with n-heptane as necessary. The organic layers werecombined and concentrated in vacuo. The crude product was purified viaSiO₂ column chromatography to yield ER-806721 (0.74-0.85 wt., 0.74-0.85eq.) as a light yellow oil.

A reactor was charged with ER-806721 (1 wt., 1 eq.) and anhydrousdichloromethane (4.2 vol.). The reaction was cooled to an internaltemperature of 0-5° C., then triethylamine (0.34 wt., 1.5 eq.),p-toluenesulfonyl chloride (0.51 wt., 1.2 eq.), and4-(dimethylamino)-pyridine (0.001 wt., 0.25 eq.) were added. Theresulting mixture was stirred at ambient temperature for 48 hours thenwater (1.8 vol.) and dichloromethane (1.8 vol.) were added. Aftersufficient mixing, the organics were separated and concentrated. Theconcentrate was dissolved in MTBE (1.8 vol.) and washed with brine (1.8vol.). The organic layer was separated and set aside. The aqueous layerwas back extracted with MTBE (1.8 vol.) then all organics were combinedand concentrated in vacuo. The crude oil was filtered through a plug ofSiO₂ (70-230 mesh, 1 wt.) eluting with MTBE (7 vol.) and the filtrateswere concentrated in vacuo. The concentrate was dissolved in IPA (5vol.) and water (0.25 vol.) was added. The resulting mixture was cooledto an internal temperature of 15° C. and then seeded with ER-807204.After seeding, the mixture was cooled to an internal temperature of 0°C. and stirred for 4-5 hours. The suspension filtered, the filter cakewas washed with cold IPA (1 vol.), and the cake dried in vacuo to aconstant weight to yield ER-807204 (1.05 wt., 0.78 eq.) as a whitepowder. IR (thin film, cm−1) λ2597, 1633, 1363, 1177, 907, 729. LRMS m/z602 (M+H).

A reactor was charged with 21% sodium ethoxide in ethanol (2.97 wt., 0.9eq.). The solution was heated to an internal temperature of 65° C. thendiethyl malonate (3.24 wt., 2 eq.) was added at a rate such that theinternal temperature did not exceed 70° C. The mixture was stirred for30 minutes and then ER-806906 (1 wt., 1 eq.) was added over 3-5 hours.Upon complete addition, the reaction was stirred for 60 minutes and thencooled to an internal temperature of 50° C. Concentrated hydrochloricacid (0.84 wt., 1.05 eq.) was added at a rate such that internaltemperature did not exceed 65° C. The DMF (3 vol.) and ethanol wereremoved via distillation then a solution of magnesium chloridehexahydrate (0.21 wt., 0.1 eq.) in distilled water (0.25 vol., 1.4 eq.)was added. The resulting mixture was heated to an internal temperatureof 135° C. while removing the distillate. The mixture was heated atreflux then cooled to room temperature and brine (12 vol.) and TBME (16vol.) were added. The organic layer was separated and washed with water(1.3 vol.) and brine (1.2 vol.) then concentrated in vacuo. The productwas purified via distillation to yield ER-805552 (0.95-1.09 wt., 0.71eq.).

A reactor was charged with LHMDS 1.0 M in toluene (6.61 wt., 1.04 eq.)and cooled to an internal temperature of −75° C. ER-805552 (1 wt., 1eq.) was dissolved in anhydrous THF and added to the reactor at a ratesuch that internal temperature did not exceed −70° C. Upon completeaddition, the resulting mixture was stirred for 30 minutes. A secondreactor was charged with anhydrous THF (2.5 vol.) and methyl iodide(1.27 wt., 1.25 eq.) and cooled to an internal temperature of −75° C.The solution of ER-805552 in THF was added into the methyl iodidesolution at a rate such that internal temperature did not exceed −65° C.Upon complete addition, the reaction was stirred at an internaltemperature of −78° C. for 30 minutes. The reaction was inverse quencheda solution of 1 N hydrochloric acid (10 vol.) and MTBE (8 vol.) withvigorous stifling. After complete addition, the aqueous layer wasseparated and discarded. The organic layer was washed with brinesolution (3 vol.) and concentrated in vacuo and the product purified viadistillation to afford ER-806724 (0.75 wt.) as a ˜6/1 mixture ofdiastereomers.

A reactor was charged with N,O-dimethylhydroxylamine HCl (1.05 wt., 1.5eq.) and anhydrous CH₂Cl₂ (8.1 vol.) and cooled to an internaltemperature of 0° C. 2 M trimethylaluminum in toluene (3.93 wt., 1.5eq.) was added at a rate such that internal temperature did not exceed5° C. The reaction was stirred for an additional 10 minutes andER-806724 was added at a rate such that internal temperature did notexceed 5° C. The reaction was diluted with CH₂Cl₂ (15 vol.) then inversequenched into 1.3 M sodium tartrate (20 vol.) at an internal temperatureof 0° C. at a rate such that the internal temperature did not exceed 10°C. After complete addition, the layers were partitioned and the aqueouslayer was separated and set aside. The organics were washed with water(1 vol.), dried over sodium sulfate (1 wt.), filtered and concentratedin vacuo until minimal methylene chloride was being removed. To theconcentrate was added anhydrous DMF (6.3 vol.), imidazole (0.64 wt., 1.5eq.) and t-butyldimethylsilyl chloride (0.94 wt., 0.97 eq.),respectively. Water (5 vol.) and MTBE (10 vol.) were added and theresulting mixture stirred then the layers were allowed to partition. Theaqueous layer was separated and discarded. The organic layer was washedwith water (5 vol.) and the layers separated. 1 N sodium hydroxide (2.5vol.) and methanol (2.5 vol.) were added and the resulting mixturestirred. The aqueous layer was separated and the organic layer washedwith brine (2.5 vol.) then concentrated in vacuo to afford ER-806753(1.94 wt., 0.91 eq.) as a brown oil.

A reactor was charged with ER-806753 (1 wt., 1 eq.), CH₂Cl₂ (5 vol.) andNMO-50% in water (0.8 wt., 1.1 eq.). The mixture was cooled to aninternal temperature of 10° C. and then 0.197 M OsO₄ in toluene (0.06vol., 0.004 eq.) was added. Sodium sulfite (0.1 wt., 0.25 eq.) and water(0.85 vol.) were added and the reaction stirred for 1 hour. The mixturewas diluted with brine (0.85 vol.) and the organics were concentrated invacuo to approximately 1/3 vol. A second reactor was charged with sodiumperiodate (1.3 wt., 2 eq.) followed by THF (2.5 vol.). The mixture wasdiluted with pH=7 phosphate buffer (3.0 vol.) and cooled to an internaltemperature of 20° C. The concentrated diol was added at a rate suchthat the internal temperature did not exceed 30° C. After completeaddition, the resulting mixture was stirred at room temperature. Water(1.25 vol.), MTBE (7 vol.) and brine solution (1.25 vol.) were added andthe layers separated. The organics were washed a second time with amixture of brine solution (1 vol.) and saturated sodium bicarbonate (1vol.). Finally, the organics were stirred over a mixture of brine (1vol.) and 10% (w/v) sodium thiosulfate solution (1 vol.) for 1 hour thenconcentrated in vacuo. The crude material was purified via SiO₂ columnchromatography to yield ER-806754 (0.93 wt., 0.93 eq.) as a yellow oil.IR (thin film, cm−1) λ2953, 2856, 1725, 1664, 1463, 1254, 1092, 833.LRMS m/z 332 (M+H).

A reactor was charged with ER-806629 (1.53 wt., 3.1 eq.) and THF (10.5vol.) and the solution was degassed with nitrogen sparge for 60 minutes.A second inerted reactor was charged with ER-807204 (1 wt., 1.0 eq.),ER-806754 (0.66 wt., 1.2 eq.) and THF (2.7 vol.) and this solution wasdegassed with argon sparge for 45 minutes. The reactor containingER-806629 was charged with CrCl₂ (0.63 wt., 3.1 eq.) and followed byEt₃N (0.52 wt., 3.1 eq.). The dark green suspension was stirred at aninternal temperature of 30 to 35° C. for 1 hour, cooled to 0 to 5° C.and then NiCl₂ (0.1 eq.) was added. The first reactor was charged withthe contents of the second reactor slowly over 0.5 hours and thereaction allowed to warm to rt. The reaction was cooled to an internaltemperature of 0° C. then ethylenediamine (1.0 wt., 10 eq.) was addedover 30 minutes and the reaction stirred at an internal temperature of25° C. for at least 30 minutes. To the reaction was added water (4vol.), TBME (10 vol.) and n-heptane (1 vol.) and the resulting mixturestirred for 15 minutes and the phases allowed to separate (˜30 min). Theaqueous phase was separated and back extracted with TBME (˜7.5 vol.).The organic layers were combined and washed with water (5 vol.), brine(3 vol.), and concentrated in vacuo to minimum volume. To the crudemixture was added IPA (10 vol.) and SiO₂ (1 wt.) and the resultingmixture stirred at an internal temperature of 25° C. for up to 4 days.The slurry was filtered and the filter cake washed with IPA (2×1volume). To the filtrate was added n-heptane (6.6 vol.) and the mixturewas concentrated in vacuo until a suspension formed. The mixture wasfiltered and the cake washed with n-heptane then the mixture wasconcentrated in vacuo. The crude product was purified via SiO₂ columnchromatography to yield ER-807524 (0.54 wt., 0.48 eq.), as a clearyellow oil. IR (thin film, cm−1) λ2934, 1668, 1471, 1108, 833. LRMS m/z704 (M+Na).

A reactor was charged with ER-807524 (1 wt., 1 eq.) and anhydrous THF(1.25 vol.). The mixture was cooled to an internal temperature of −20°C. and 3 M methyl magnesium chloride (0.59 vol., 1.2 eq.) was added at arate such that the internal temperature did not exceed 0° C. Uponcomplete addition, the mixture was warmed to an internal temperature of0° C. over 2 hours. The reaction mixture was inverse quenched intosemi-saturated ammonium chloride (2.62 vol.) and the resulting mixturediluted with TBME (2 vol.) with vigorous mixing. The aqueous layer wasdiscarded and the organics washed with brine (2 vol.) then concentratedin vacuo. The crude product was purified via SiO₂ column chromatographyto yield ER-807525 (0.79-0.82 wt., 0.85-0.88 eq.) as yellow oil.

A reactor was charged with ER-807525 (1 wt., 1 eq.),N-phenylbistrifluoromethanesulfonamide (0.59 wt., 1.1 eq.), andanhydrous THF (4.1 vol.) and the mixture cooled to an internaltemperature of −75° C. 0.5 M KHMDS in toluene (2.75 wt., 1 eq.) wasadded at a rate such that internal temperature did not exceed −60° C.then the reaction was warmed to −20° C. over 2 hours. The reaction wasquenched with semi-saturated NH₄Cl (2.4 vol.) at a rate such thatinternal temperature did not exceed 0° C. The mixture was warmed to aninternal temperature of 20° C. and n-heptane (2.4 vol.) was added. Themixture was stirred and the aqueous layer was separated and discarded.The organic layer was washed three times with saturated sodiumbicarbonate (2.3 vol. each) then concentrated in vacuo to yieldER-807526 (1.2-1.4 wt., 1.0-1.2 eq.). The material was utilized in thenext stage without further purification.

A reactor was charged with ER-807526 (1 wt., 1 eq.) and anhydrousmethanol (3 vol.) at 20° C. 1.25M HCl in IPA (4 vol., 5 eq.) was addedand the mixture stirred for 3 hours. Solid NaHCO₃ (0.42 wt., 5 eq.) wasadded portion-wise with stirring until the pH of the reaction mixturereached 6-7. The reaction mixture was filtered with methanol (3×2 vol.)washes. All filtrates were concentrated in vacuo and then purified viaSiO₂ column chromatography to yield ER-807527 (0.43 wt., 0.79-0.85 eq.).

The diastereomeric mixture of ER-807527 was separated by preparativeHPLC chromatography and the desired fractions concentrated to yieldER-806730 (0.56 wt., 0.56 eq.) as a clear yellow oil. The preparativeHPLC chromatography protocol used to isolate ER-806730 is as follows.

-   -   Column and Media: Kromasil spherical silica 60 Å, 10 μm particle        size packed to 7.7 cm (diam.)×30 cm (length) in a 7.7 cm×60 cm        Varian Dynamax Rampak column.    -   HPLC Packing Station: Varian (Rainin) Dynamax Rampak 41/77 mm        Column Packing Station    -   HPLC Pumps: Varian (Rainin) SD-1 Titanium Pump Heads    -   Primary HPLC Detector: Waters R403 Refractive Index detector    -   Secondary HPLC Detector: Varian (Rainin) UV-1 detector with        preparative flow cell    -   Chromatography Control    -   and Acquisition Software: Varian (Rainin) Dynamax DA version        1.4.6    -   Chromatography Data    -   Processing Software: Varian (Rainin) Dynamax R version 1.4.3    -   Mobile Phase: 28.5:63.7:7.85 (vol/vol) n-heptane:methyl        tert-butyl ether:2-propanol    -   Flow Rate: 140 mL/min    -   Column Temperature Ambient (25° C.)    -   Detection: Refractive Index, negative polarity at 16×        attenuation and UV at 215 nm.    -   Mobile Phase Gradient: Isocratic    -   Run Time: 40 minutes    -   Injection Volume: 10 ml of 0.8 g/mL of ER-807527

The above protocol was used to separate the diastereomers of ER-807527in the following manner. Each lot of ER-807527 was first diluted to 0.1g/ml in the mobile phase and filtered under vacuum through a 47 mm, 1 μmpore size, glass fiber filter (Whatman GFC). The filtrate was thenconcentrated under vacuum on a rotary evaporator. Flow on the SD-1 HPLCpump A (primed and purged with mobile phase) was initiated and the flowrate gradually increased to 140 mL/minute. The system was washed untilthe UV and RI detectors achieved a stable baseline. The RI detectorreference flow cell was flushed with fresh mobile phase.

Chromatography of 8 g injections of ER-807527 was accomplished bydiluting the current lot of ER-807527 to a concentration of 0.8 g/mL inthe mobile phase. Injecting 10 mL aliquots of the dissolved material andcollecting the eluant corresponding to the ER-806730 peak approximatelybeginning at the peak apex approximately 24 minutes and continuing to 35minutes. Subsequent injections and fraction collection were continueduntil the starting material is exhausted.

The fractions corresponding to ER-806730 were pooled and concentratedunder vacuum on a rotary evaporator. The diastereomeric purity andarea-% purity area were assessed using the HPLC analytical methoddescribed in Table 2.

TABLE 2 HPLC Analysis of Diastereomeric Purity of ER-806730: Column:Kromasil Slica 250 x 4.6 mm, 5 μm , MetaChem cat. no. 0475-250X046 Flowrate: 1 mL/min Temp. (° C.): 27 Inj. Vol.: 10 uL, sample in Solvent A,2.5 mg/mL Instrument: Waters Alliance W2690 with UV W2487 Mobile PhaseConstituents: A 30:67:3 n-Heptane: Methyl tert-Butyl Ether:2-Propanol B2-Propanol C D Gradient Table: (%) Time (min) A B C D Gradient  0 100 00 0 isocratic 22 100 0 0 0 isocratic 26  90 10  0 0 linear 32  90 10  00 isocratic Run time 32 min with 18 min re-equilibration time at initialconditions Detection: Absorbance at 205 nm UV

A reactor was charged with ER-806730 (1 wt., 1 eq.) and anhydrousdichloromethane (4.8 vol.) and cooled to an internal temperature of 0°C. 2,4,6-Collidine (1.16 wt., 4 eq.) and DMAP (0.03 wt., 0.1 eq.) wereadded and the resulting mixture stirred for 15 minutes and thentrimethylacetyl chloride (0.3 wt., 1.05 eq.) was added at a rate suchthat internal temperature did not exceed 10° C. Water (3 vol.) was addedand the mixture stirred for 15 minutes. TBME (10 vol.) was added and themixture stirred for an additional 10 minutes. The organic layer waswashed with 1N HCl (10 vol.) washing until a negative result for2,4,6-collidine is obtained then with water (5 vol.), saturated sodiumbicarbonate (5 vol.), and saturated brine (5 vol.), respectively. Theorganic layer was concentrated in vacuo and the concentrate purified viaSiO₂ column chromatography to yield ER-806732 (1.02 wt., 0.85 eq.) as ayellow oil.

A reactor was charged with ER-806732 (1 wt., 1 eq.) and anhydrous THF(2.35 vol.) and cooled to an internal temperature of 0° C. Triethylamine(0.22 wt., 1.1 eq.) was added followed by methanesulfonyl chloride (0.24wt., 1.05 eq.) at a rate such that internal temperature did not exceed10° C. The reaction was stirred at an internal temperature of 0° C. thenn-heptane (3.4 vol.) was added with vigorous stirring and the layerswere allowed to partition. The organics were washed with saturated brine(3.4 vol.), dried over saturated sodium sulfate (2 wt.), filtered andthe cake washed with n-heptane until a negative result for ER-805973(F-2a) was obtained. The filtrates were concentrated in vacuo to obtainER-805973 (1.12 wt., 0.97 eq.). The crude ER-805973 (F-2a) was used inthe next stage without further purification. IR (thin film, cm−1) λ2961,1725, 1413, 1208, 926. LRMS m/z 579 (M+H).

Example 3 Alternate Preparation of ER-806730

Quinic acid (1 wt), cyclohexanone (2.11 eq, 1.08 wt), and conc. sulfuricacid (0.011 eq, 0.0056 wt) were added to a reactor. The reaction mixturewas heated to 160° C. and water was removed by azeotropic distillation(azeotrope begins at 100° C.). The reaction was cooled to 90° C. to 100°C. and sodium bicarbonate (0.0096 wt) and toluene (3.6 wt) were added.The reaction was cooled to ambient temperature over 4-6 hours and theresulting precipitate was filtered, washed with toluene (2×0.9 wt), anddried to provide 1 (0.97 wt) as a white powder.

Compound 1 (1 eq, 1 wt) and imidazole (2.5 eq, 0.80 wt) were combined,purged with N₂, and suspended in anhydrous THF (10 v). TMSCl (1.2 eq,0.61 wt) was added at a rate that maintained the temperature below 30°C. The reaction was cooled to ambient temperature, heptane (10 v) wasadded and the resulting suspension filtered. The filter cake was washedwith 1:1 hpt/THF (10 v) the filtrate solvent was exchanged with tolueneby atmospheric distillation to provide a solution of 2a (calcd. at 1.34wt) in toluene (˜5 wt).

The solution of 2a was cooled to −78° C. and DIBAL-H (1.5 M in toluene,1.2 eq, 2.1 wt) was added at a rate that maintained the temperaturebelow −65° C. The excess DIBAL-H was quenched with MeOH (0.3 eq, 0.034wt) and the solution warmed to 0° C. The solution was transferred to asolution of 30% wt/wt aqueous Rochelle salt (10 wt) and sodiumbicarbonate (1 wt) at a rate that maintained the temperature below 25°C. The mixture was stirred vigorously to obtain a biphasic solution. Thelayers were separated and the aqueous layer was extracted with MTBE (5v). The combined organic layers were washed with water (2.5 wt) and thensaturated brine (2.5 wt). The organics were concentrated and solventexchanged with THF to provide a solution of 2b (calcd. at 0.98 wt) inTHF (5 v).

The solution of 2b was cooled to 5° C. and acetic acid (2.9 eq, 0.51 v)was added. Water (1.0 eq, 0.055 v) was added and the solution stirred at0° C. to 5° C. Up to two additional aliquots of acetic acid and onealiquot of water were added as needed to facilitate deprotection of thesilyl group. Et₃N (12 eq, 3.6 wt) and DMAP (0.05 eq., 0.02 wt) wereadded at a rate that maintained the temperature below 20° C. Aceticanhydride (6 eq, 2.0 wt) was added and the reaction stirred at rt. Thereaction was cooled to 5° C. and added to saturated aqueous sodiumbicarbonate (10 v) at a rate that maintained the temperature below 30°C. The resulting mixture was allowed to stir for 3-4 hours and thelayers allowed to separate. The aqueous layer was extracted with MTBE (5v) and the combined organics were washed with water (5 v). The extractswere solvent exchanged with IPA by distillation to provide a solution of2c in IPA (3 v). The solution was cooled to 5° C. and the resultingcrystals were filtered. The mother liquor was concentrated and a secondcrop obtained after recrystallization to provide 2c (0.87 wt) as a whitecrystalline solid.

2c (1 wt) was dissolved in acetonitrile (6 v) and methyl3-trimethylsilylpent-4-eneoate (3.0 eq, 1.86 wt) was added followed byTFAA (0.2 eq, 0.083 v). BF₃.0Et₂ (1.0 eq, 0.42 v) was then added to thesolution at a rate that maintained the temperature below 25° C. Thereaction was added to saturated aqueous sodium bicarbonate (10 v) andthe resulting mixture stirred for 15 minutes. The mixture was extractedwith heptane (10 v), followed by MTBE (5 v) and the combined extractswere concentrated to provide 3 (calcd. at 0.72 wt) as an orange oil.

A solution of 3 (1 wt) in THF (9 v) was treated with sodium methoxide(25% wt/wt in methanol (1.5 eq, 2.2 wt)) at a rate that maintains thetemperature below 25° C. The reaction was quenched by addition to 1 NHCl (10 v). The organic layer was separated and the aqueous wasextracted with MTBE (10 v). The combined organics were washed with water(2.5 v), saturated sodium bicarbonate (2.5 v), and water (2.5 v). Thesolution was concentrated to provide a solution of 4 (calcd. at 0.88 wt)in THF (2.5 v). The solution was used directly in the next step.

Methanol (5 v) was added to the solution of 4 (1 wt) in tetrahydrofuran(2.5 v). 1N HCl (0.75 eq, 2 v) was added and the reaction was warmed to60-80° C. The reaction was cooled to rt and added to saturated aqueousbicarbonate. The mixture was extracted with DCM (3×2.5 v) and thecombined DCM extracts were solvent exchanged with EtOAc to provide asolution of 5 in EtOAc (3 v). Heptane (2 v) was added to inducecrystallization and the resulting suspension cooled to 0° C. The solidswere collected by filtration and the filter cake washed with coldEtOAc/heptane (1:1 v/v) and dried to provide 5 (0.55 wt) as a whitepowder.

Compound 5 (1 wt) was dissolved in ACN (10 v) then2-acetoxy-2-methylpropanyl bromide (4.0 eq, 2.2 wt) and water (1 eq,0.067 wt) were added consecutively. The resulting mixture was stirred atambient temperature then cooled to 5-10° C. NaOMe (25% wt/wt in MeOH, 8eq, 6.2 wt) was added and the reaction allowed to warm to ambienttemperature. The reaction was quenched by the addition of saturatedsodium bicarbonate (10 v) and extracted with MTBE (2×10 v). The solventwas exchanged with methanol by atmospheric distillation to provide asolution of 6 (calcd at 0.91 wt) in methanol (10 v).

A solution of 6 (1 wt) in methanol (10 v) was heated to 55° C. Sodiumborohydride (5 eq, 0.68 wt) was added in 6 portions and the reactioncooled to 5° C. and quenched with 1 N HCl (10 v). Brine (5 v) was addedand the reaction extracted with EtOAc (2×10 v). The extracts werecombined and concentrated to provide 7 as a tan residue.

Compound 7 (1 wt) was dissolved in CH₂Cl₂ (10 v) then DMAP (0.1 eq,0.054 wt), Et₃N (3.0 eq, 1.85 v), and TBDPSCl (1.2 eq, 1.38 v) wereadded at ambient temperature. Sodium bicarbonate (10 v) was added andthe organic layer separated. The aqueous layer was extracted again withCH₂Cl₂ (10 v), the organic extracts combined and concentrated to provide8 (calculated at 1.8 wt) as a colorless oil.

LDA (1.5 M in cyclohexane, 4 eq, 6 v) was added to a solution of 8 (1wt) in THF (10 v) at ambient temperature. The solution was warmed to 50°C. then quenched with 1 N HCl (5 v) and extracted with MTBE (10 v). Theextracts were concentrated to provide 9 (0.9 wt) as an oil.

A solution of 9 (1 wt) in CH₂Cl₂ (5 v) in MeOH (5 v) was cooled to −60°C. and treated with O₃ keeping temperature below −50° C. The reactionwas purged with N₂, NaBH₄ (0.5 eq, 0.04 wt) was added and the mixturewarmed to 0° C. Additional NaBH₄ (1 eq, 0.08 wt) was added in portionsand the reaction allowed to warm to ambient temperature. After 3 hours,the mixture was quenched with 1N HCl, (10 v), CH₂Cl₂ (5 v) was added andthe layers were allowed to partition. The aqueous layer was re-extractedwith CH₂Cl₂ (10 v) and the organic extracts were combined andconcentrated to provide 10 (0.97 wt) as a colorless oil.

Compound 10 was dissolved in THF (10 v) and phosphate buffer (pH=7, 5 v)was added. NaIO₄ (2 eq, 0.854 wt) was added and the reaction warmed toambient temperature. Water (5 v) and MTBE (10 v) were added and theresulting mixture was stirred vigorously for 10 minutes. The organiclayer was separated and washed with 10% wt/v aqueous sodium thiosulfate(5 v), water (5 v), and brine (5 v) then dried by azeotropicdistillation with THF (˜200 ppm water) to provide a solution of 11(calcd. at 0.93 wt) in THF (10 v). This solution was used directly innext step.

(Carbomethoxymethylene)triphenylphosphorane (1 wt) was added to thesolution of 11 (1 wt) in THF (10 v) and heated to 65° C. Heptane (40 v)was added and the resulting mixture stirred for 30 minutes. Theresulting precipitate was filtered and the filtrate concentrated to atotal 10 v. SiO₂ (5 wt) was added and the suspension filtered over a padof SiO₂ eluting with MTBE (20-40 v). The solvent was exchanged with MeOHto provide a solution of 12 (calcd. at 0.95 wt) in MeOH (10 v) which wasused directly in the next step.

A solution of 12 (1 wt) in MeOH (10 v) was added to 10% wt/wt Pd(C)(0.23 eq, 0.37 wt) and treated with H₂. The suspension was filteredwhile rinsing the filter cake with THF (10 v). The solvent was exchangedwith THF to provide a solution of 13 (calcd. at 0.95 wt) in THF (10 v)which was used directly in the next step.

The solution of 13 (1 wt) in THF (10 v) was cooled to 0-5° C. and LAH (1M (THF), 0.78 eq, 1.5 v) was added at a rate that maintained thetemperature below 10° C. Water (1.7 eq, 0.06 v) was then added at a ratethat maintained the temperature below 10° C. NaOH (10% wt/wt in water,0.16 eq, 0.06 v) was added followed by water (4.98 eq, 0.17 v) at a ratethat maintained the temperature below 10° C. and the resulting mixturestirred vigorously while warming to ambient temperature. The suspensionwas filtered and the filter cake rinsed with THF (5 v). The filtrate waspartially concentrated to provide 14 (calcd. at 0.9 wt) in THF (10 v)which was used directly in next step.

The solution of 14 (1 wt) in THF (10 v) was cooled to 0° C. thenimidazole and TrCl (1.5 eq, 0.59 wt) were added. Saturated aqueousNaHCO₃ (5 v) was added and the mixture extracted with heptane (10 v).The extract was washed with brine (10 v) and concentrated to provide 15(1.35 wt).

Compound 15 (1 wt) was dissolved in THF (10 v) and treated with TBAF(1M, 1.2 eq, 1.6 v). The reaction mixture was concentrated to 2 v thenheptane (5 v) and SiO₂ (5 wt) were added. The resulting suspension wasfiltered and eluted with heptane (5 v) followed by THF (10 v). The THFeluent was collected to provide a solution of 16 (calcd at 0.61 wt) inTHF (10 v) which was used directly in the next step.

PPh₃ (5 eq, 2.3 wt), pyridine (10 eq 1 vol), and NIS (3.0 eq, 1.1 wt)were added to the solution of 16 (1 wt) in THF (10 v). 20% wt/wt aqueouscitric acid (10 eq, 14 wt) was then added and the resulting mixtureallowed to stir for 10 minutes. The reaction was diluted with heptane(10 v) and the aqueous layer separated. The organic layer was washedwith water (5 v), 10% wt/v aqueous sodium thiosulfate (5 v), water (5 v)and brine (5 v). The solvent was exchanged with EtOH and concentrated to5 v. Water (10 v) was added and the resulting precipitate was collectedby filtration to obtain 17 (0.65 wt) as a white solid.

Compound 17 (1 wt) and KCN (6 eq, 0.54 wt) were suspended in EtOH (5 v)and water (10 v) and the resulting suspension heated to 80° C. Thereaction was diluted with water (5 v) and EtOAc (10 v) and mixed for 10minutes. The aqueous layer was removed and the organic layer washed withwater (5 v) and brine (5 v). The solvent was exchanged with EtOH toprovide 18 (0.75 wt) in EtOH (10 v) which was used directly in nextstep.

Zn (37 eq, 3.9 wt) was added to the solution of 18 (1 wt) in EtOH (10 v)and the mixture heated to 75-80° C. The reaction was partiallyconcentrated to 2-3 v, cooled to ambient temperature, and partitionedbetween MTBE (10 v) and water 5 (v). The aqueous layer was removed andthe organic layer washed with saturated bicarbonate (5 v), water (5 v),and brine (5 v), then dried by THF azeotropic distillation to ˜200 ppmwater to provide 19 (0.81 wt) in THF (10 v). The resulting solution wasused directly in next step.

LDA (1.0 M in THF, 1.2 eq, 2.4 v) was added to the solution of 19 (1 wt)in THF (10 v) at −78° C. The resulting mixture was stirred for 10minutes then the enolate solution was added to a solution of MeI (1.5eq, 0.19 v) in THF (5 v) at −78° C. The reaction was inverse quenchedinto saturated sodium bicarbonate (10 v) and extracted with MTBE (15 v).The extract was washed with brine (5 v), concentrated, then purified bychromatography to provide 20 (0.86 wt).

AlMe₃ (2 M in toluene, 1.5 eq, 1.5 v) was added to a suspension ofdimethylhydroxylamine hydrogen chloride (1 wt) in CH₂Cl₂ (2.5 v) at 0°C. A solution of 20 (1 wt) in CH₂Cl₂ (5 v) was added at a rate thatmaintained the reaction temperature below 5° C. The reaction mixture wasthen added to aqueous sodium tartrate (1.3 M, 20 v) keeping thetemperature below 10° C. The layers were allowed to partition, wereseparated, and the organic layer was dried with Na₂SO₄ (5 wt). Theresulting suspension was filtered and the filtrate concentrated. Theresidue was dissolved in DMF (2 v) then imidazole (0.19 wt) and TBSCl(0.29 wt) were added. The reaction was diluted with water (5 v) and MTBE(10 v) and allowed to stir for 10 minutes. The aqueous layer was removedand the organic layer washed with water (5 v). The extract was added toa solution of aqueous NaOH (1N, 0.78 v) and MeOH (0.7 v). The reactionwas allowed to stir then the aqueous layer was removed and the organiclayer was washed with brine (2.5 v) then concentrated to provide 21 (1.2wt).

Methyl magnesium chloride (3.0 M, 59 wt, 1.2 eq) was added to a solutionof 21 (1 wt) in anhydrous THF (1.11 wt, 1.25 v) at a rate thatmaintained the reaction temperature below 0° C. After stirring at 0° C.,the reaction was reverse quenched into saturated ammonium chloride (2.5v) and water (2.3 v). The resulting mixture was diluted with MTBE (10 v)and stirred vigorously. The aqueous layer was separated and the organiclayer washed with brine (2.5 v) and concentrated to provide 22 (0.84wt).

Compound 22 (1 wt) was dissolved in THF (4 v) and cooled to −78° C.KHMDS (1.5 M in toluene, 1.01 eq, 2.78 wt,) was added while maintainingthe temperature below −60° C. A solution of Tf₂NPh (0.62 wt, 1.1 eq) inTHF (1.5 v) was added and the reaction warmed to −20° C. Saturatedammonium chloride (2.5 v), water (2.5 v), and n-heptane (2.5 v) wereadded and the mixture warmed to ambient temperature. The layers wereallowed to partition and the aqueous layer removed. The organic extractwas washed with saturated aqueous sodium bicarbonate (3×2.5 v) and brine(2.5 v) then concentrated in vacuo to provide 23 (1.1 wt).

Compound 23 was dissolved in MeOH (2.5 v) and cooled to 15° C. HCl (5Nin IPA, 1.30 eq, 1.18 wt) was added and the resulting solution allowedto warm to 25° C. The reaction was cooled to 0° C. and sodiumbicarbonate (3 eq, 0.33 wt) was added. The reaction was stirred for 15minutes and the resulting precipitate removed by filtration. The filtercake was washed with ACS grade methanol (1 v) and filtrates werecombined and concentrated. The crude concentrate was purified bychromatography to provide ER-806730 (24) (0.5 wt).

Example 4a

Example 4a provides an alternate method of preparing compounds offormula A, an intermediate to F 2, using the general scheme set forth atScheme V above. This method uses ER-812935 as an intermediate asprepared according to Example 3 (compound 4), above.

ER-812935 (1 wt) was dissolved in THF (10 v) and cooled to 0° C. LAH(1.0 M in THF, 0.70 eq, 2.0 v) was added keeping the temperature below5° C. While stirring vigorously, excess reagent was quenched with water(0.078 v) keeping the temperature below 5° C. While maintaining thevigorous stifling, NaOH (15% wt/wt in water (0.078 v)) was addedfollowed by water (0.18 v). After adding Celite® (2 wt), the suspensionwas filtered and the cake rinsed with THF (5 v). The solution ofER-817633 (0.92 wt, calcd. based on 100% conversion) was concentrated to5 v and used directly in the next stage.

The previously prepared solution of ER-817633 (1 wt in 5 v THF) wasdiluted with THF (5 v), cooled to 5° C. and Et₃N (3 eq., 0.94 wt) wasadded. MsCl (1.05 eq, 0.25 v) was added at a rate that maintained thetemperature below 10° C. The reaction was quenched by addition of water(5 wt). Heptane (8 v) was added and the mixture allowed to partition.The aqueous phase was separated and extracted with MTBE (2 v). Thecombined organic extracts were washed with saturated sodium bicarbonate(5 v) and water (1.9 v) The organic layer was concentrated and solventexchanged with EtOH to prepare a solution of ER-818937 (1.23 wt calcd.based on 100% conversion) in EtOH (1 v) which was used directly in thenext stage.

The previously prepared solution of ER-818937 (1 wt in EtOH (0.8 v) isdiluted with EtOH (190 proof, 9 v). KCN (3 eq., 0.41 wt) was added andthe suspension was heated to 70-80° C. The reaction was cooled toambient temperature and water (10 v) was added followed by MTBE (10 v).The layers were separated and the aqueous extracted with MTBE (5 v). Thecombined organics are washed with water (2 v) and saturated brine (4wt). The extracts were concentrated and used directly in the next stage.

ER-818950 was dissolved in acetic acid (5 v) and hydrogen chloride (1.0M, 1 eq, 3 v) was added and the reaction was stirred at ambienttemperature. The reaction was cooled to 0° C. and NaOH (50% wt/wt, 30eq, 7 wt) was added at a rate that maintained the temperature below 10°C. The solution was extracted with heptane (2×10 vol). The aqueous phasewas saturated with NaCl and extracted with ACN (2×10 v). The combinedACN extracts were concentrated and solvent exchanged with EtOAc byatmospheric distillation to provide a solution of ER-817664 in EtOAc (3v). Salts were filtered from the hot solution which was then cooled to0° C. The suspension was filtered to provide ER-817664 as a whitecrystalline solid.

Example 4b

Example 4b provides an alternate method of preparing compounds offormula F-2 using the general scheme set forth at Schemes Vb and Vcabove. This method uses ER-817664 as an intermediate as preparedaccording to Example 4a, above.

ER-817664 (1 wt) was dissolved in ACN (10 v), the suspension was cooledto 0° C. and 2-acetoxy-2-methylpropanyl bromide (4.0 eq, 2.4 v) wasadded followed by the addition of H₂O (1.0 eq., 0.07 v). The resultingmixture was stirred at 0° C. for 2 hours. NaHCO₃ (sat. aqueous, 8.0 eq.40 v) was added slowly at 0° C. The resulting mixture was stirred atroom temperature for 30 minutes prior to extraction with MTBE (2×20 v).The organic layer was washed with brine (5 v) and concentrated to givethe product as colorless oil.

The starting bromide (1 wt), depicted immediately above, was dissolvedin toluene (10 v). DBU (1.8 eq., 0.73 v) was added and the mixture washeated at 80° C. The mixture was cooled to room temperature, dilutedwith MTBE (20 v), and washed with water (5 v) and then brine (5 v). Theorganic layer was then concentrated to give the product as an off-whitepowder.

The starting olefin compound (1 wt), depicted immediately above, wasdissolved in CH₂Cl₂ (5 v) and MeOH (5 v), and cooled to between −40° C.to −45° C. The solution was then treated with O₃. Excess O₃ was removedby N₂ purge and the solution was warmed to −15° C. NaBH₄ (1.0 eq, 0.18wt) was added and the mixture was warmed to 0° C. K₂CO₃ (1.3 eq.) wasadded and the suspension stirred at rt. The reaction was neutralizedwith 1N HCl (˜4 eq, ˜20 v) at 0° C. and the solution was extracted withMTBE (10 v) to remove lypophilics. The aqueous layer was concentrated toremove CH₂Cl₂ and MeOH. THF (4 v) was added followed by NaIO₄ (2 eq, 2wt). The reaction was extracted with MTBE (10 v) and n-BuOH (10 v). Thecombined organic extracts were concentrated and the resulting powder wastriturated with EtOAc. After filtration the lactol was isolated as apale yellow powder.

ER-818638 (1 wt) and LiCl (2.0 eq, 0.35 wt) was stirred in ACN (8.7 v).Hunig's base (1.5 eq) was added at 25° C. 1 N HCl (5 v) was added andthe mixture was extracted with MTBE (10 v). The organics wereconcentrated to provide ER-818640 which was used as is in the next step.

The starting α-olefin ester compound (1 wt), depicted immediately above,was dissolved in MeOH (10 v) and added to 10 wt % of Pd(C) (0.09 eq,˜0.33 wt) under N₂. The suspension was then stirred under H₂. Thesuspension was filtered through a Celite® pad (20 wt), rinsing thefilter cake with MeOH (20 v). The filtrate was concentrated and purifiedby flash chromatography to give product as colorless oil (94.3% yield).

Pyridine (10 eq.), Ph₃P (7 eq.) and NIS (4 eq.) were added to thesolution of the ester (1 wt) in THF (15 v) separately. The reactionmixture was stirred at ambient temperature. Aqueous citric acid (20 wt%, 10 eq) was added and the mixture diluted with TBME (30 v). Theaqueous layer was separated and the organic layer washed with water (5v), aqueous Na₂S₂O₃ (10% wt/v, (5 v), water (5 v) and brine (5 v). Theorganic layer was concentrated and purified by flash chromatography togive product as colorless oil.

The starting iodide (1 wt) was dissolved in MeOH (30 v) and heated to55° C. NaBH₄ (47 eq.) was added in 6 portions at 55° C. over 80 minutes.The reaction was cooled to 0° C. and quenched with 1N HCl (30 v). Afterstifling 5 minutes, the mixture was diluted with brine (30 v) andextracted with DCM (50 v×2). The organic layer was dried over Na₂SO₄ andconcentrated. The crude product was used directly in the next step.

The starting alcohol (1 wt), depicted immediately above, was dissolvedin EtOH (70 v) and Zn (165 eq.) was added. The suspension was refluxedat 75-80° C. The reaction mixture was cooled to ambient temperature and1N HCl (70 v) was added. The mixture was extracted with DCM (3×100 v),the organic layer washed with brine and concentrated.

The starting lactone, as depicted immediately above, was dissolved inDCM (50 v), Et₃N (5.0 eq.), DMAP (0.3 eq.) and TBDPSCl (1.5 eq.) wereadded separately at ambient temperature under N₂, and the resultingsolution was stirred at ambient temperature for 2-3 hours. Upon thecompletion of the reaction, the mixture was diluted with TBME (100 v),washed with sat. aq. NaHCO₃ solution (10 v), H₂O (10 v) and brine (10v). The organic layer was concentrated and purified by flashchromatography to give the product as colorless oil.

Example 4c

Example 4c provides another alternate method of preparing compounds offormula F-2 using the general scheme set forth at Scheme VII above. Thismethod uses ER-811510 as an intermediate as prepared according toExample 3, above where acetone is used instead of cyclohexanone.

ER-811510 (1 wt, 1 eq) was dissolved in methylene chloride (6.3 v) andcooled to −5° C. Pyridine (0.41 vol, 1.1 eq) was added followed bybromoacetyl bromide (0.44 vol, 1.1 eq) while keeping the temperaturebelow 0° C. The reaction was stirred at 1 hour and warmed to roomtemperature. Water (8 vol) was added and the layers separated. Theorganic layer was washed sequentially with aqueous copper sulfatepentahydrate (1.0 M, 10 vol), water (8 vol), and brine (10 vol) thendried over magnesium sulfate, filtered and concentrated in vacuo toafford ER-812771 as a tan solid.

ER-812771 (1 wt, 1 eq) was dissolved in acetonitrile (6 v) andtriphenylphosphine was added and the reaction heated at 50° C. for 45minutes. The reaction was cooled to −10° C. then1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 0.35 vol, 0.8 eq) was added.The reaction was stirred for 15 minutes, heated to 80° C. for 45 minutesthen cooled to ambient temperature. Ammonium chloride (saturatedaqueous, 10 vol) was added and the aqueous layer extracted with ethylacetate (3×10 v). The combined organic layers were dried over magnesiumsulfate and concentrated in vacuo. The crude product was purified bychromatography to afford ER-812772 as a white solid.

ER-812772 (1 wt, 1 eq) was dissolved in ethyl acetate (8 v). 10%Palladium on carbon (0.05 wt, 0.01 eq) was added, the reaction purgedwith nitrogen then stirred under hydrogen atmosphere for 2 hours. Thecatalyst was removed by filtration through Celite with ethyl acetatewashed. The combined filtrates were concentrated in vacuo to affordER-812829 as a white solid.

Example 5 Preparation of F-3a

D-Gulonolactone (1 wt., 1 eq.), cyclohexanone (2 to 3 eq.), toluene (6vol.), and p-toluenesulfonic acid (0.021 wt., 0.02 eq.) were charged tothe reaction vessel. Reaction mixture was heated to reflux withstirring. Upon azeotropic removal of water the reaction was complete.The reaction mixture was cooled to 85 to 90° C. and agitation wasincreased. Heptane (5.2 vol.) was added over 20-30 minutes withstirring. Cooled to 65-70° C. and stirred for 30 minutes at 65-70° C.The solid product was filtered at 65-70° C., maintaining mother liquortemp>35° C. Re-filtered at 35-40° C. and maintained the mother liquor atambient temperature for 30 minutes. Re-filtered the mother liquor. Thefilter cake was washed two times with heptane (2×1.7 vol.) then dried toafford ER-805715. Yield 84% (1.6 wt.).

In an alternate method for preparing ER-805715, D-gulonolactone (1 wt),cyclohexanone (1.32 wt, 2.4 eq), p-TsOH-monohydrate (0.02 wt, 0.02 eq)and toluene (12 vol) were refluxed together for 19 hours, whileazeotropically removing water. The mixture was washed with 5% aqueousNaHCO₃ (4 vol) followed by saturated aqueous NaCl (2 vol×2, pH=7). Theorganic phase was concentrated by distillation (ca. 4.5 vol of tolueneremaining) and cooled to 100° C. before heptane (10 vol) was added,maintaining internal temperature>80° C. The mixture was heated to refluxfor at least 1 hour before it was cooled to and aged at 85° C. for 3hours, at 80° C. for 3 hrs and then cooled to 40° C. in 12 hrs. Theproduct was collected by filtration and the cake washed with heptane (2vol). The filter cake was dried by airflow to afford ER-805715 (1.48 wt)in 78% of yield.

ER-805715 (1 wt., 1 eq.) was charged to reaction vessel and dissolved inanhydrous THF (3.34 vol.) and anhydrous toluene (2.5 vol.). The mixturewas cooled to −15 to −10° C. DIBALH (1.5M in toluene, 2.4 vol., 1.2 eq.)was added over 1 hour and the mixture stirred for 15-30 minutes at −15to −10° C. The reaction was inverse quenched into KNa-Tartrate solution(1 wt. KNa Tartrate in 2.9 wt. water) at 10° C. and the resultingmixture allowed to warm to room temperature and stir for 4 hours. Themixture was filtered then the layers separated and extracted with MTBE(2 vol.). The organic layers were combined and the solvents removed invacuo to afford ER-805814. Yield 100%, (1.02 wt.).

ER 805814 (1 wt.) was dissolved in anhydrous THF (3.3 vol.) and treatedwith (methoxymethyl)triphenylphosphonium chloride (2.11 wt., 2.1 eq.).The reaction mixture was heated to 28-32° C. then a solution of KOtBu(0.66 wt., 2 eq.) in anhydrous THF (2.64 vol.) was added over 100-140minutes, maintaining reaction temperature 30-35° C. After 5 hours, thereaction was cooled to 20-25° C., MTBE (5.11 vol.) was added and themixture stirred. Brine (3 wt.) and water (3 wt.) were added (exothermicat start of addition, controlled by bath @ 20-25° C.). Organic layer wasseparated and treated with a solution of maleic anhydride (0.27 wt.) inMTBE/THF (1/1 v/v, 1.78 vol.). NaOH solution (0.088 wt. in 2.5 vol.water) was added slowly to the reaction mixture. The organic layer wasconcentrated to give crude ER 805815 (0.985 wt.). The residue wastriturated three times with MTBE/heptane (1/4 v/v, 6.6 vol.). Theextract was filtered through SiO₂ (3 wt), eluting with MTBE/heptane (1/2v/v, 45 vol.). The filtrate was concentrated to give ER-805815 (0.88wt., 81% yield).

In an alternate method for preparing ER-805815, a solution of t-BuOK(0.989 wt, 3 eq) in THF (4 wt) was added to a suspension of(methoxymethyl)triphenylphosphonium chloride (3.12 wt, 3.1 eq) in THF(1.78 wt), maintaining the reaction temperature between 0-10° C. Theaddition vessel was rinsed with THF (2×0.7 wt). A solution of ER-805814(1 wt, 1 eq) in THF (1.42 wt) was added to the reaction, maintaining0-10° C. The addition vessel was rinsed with THF (2×0.7 wt). The mixturewas stirred at 20-30° C. overnight and 30-35° C. for 3 hours. Thereaction was cooled below 30° C. and diluted with MTBE (3.7 wt) followedby 10 wt % aqueous NaCl (4 wt) solution. The mixture was stirred for 30minutes and the layers were separated. Maleic anhydride (0.63 wt, 2.2eq) was added and the mixture stirred at room temperature for 30minutes. Water (6 wt) and a solution of NaOH (48 wt %, 0.64 wt, 2.6 eq)was added dropwise, maintaining the reaction below 15° C. After stirringbelow 15° C., the lower layer was separated. Water (6 wt) was addedfollowed by a solution of NaOH (48 wt %, 0.64 wt, 2.6 eq), keeping themixture below 15° C. during the addition. After stirring below 15° C.,the lower layer was separated. The organic layer was washed three timeswith a 15 wt % aqueous NaCl solution (3×4 wt). The organic layer wasconcentrated in vacuo. The residue was diluted with MTBE (1 wt) andconcentrated in vacuo. The residue was diluted dropwise with IPE (3 wt)at 40-50° C. over 30 minutes. The suspension was stirred for 1 hour at40-50° C. and slowly cooled to 0-10° C. and stirred for 1 hour. Thesolids were filtered and the cake washed with IPE (2 wt). The filtrateand washings were concentrated in vacuo. The residue was treated withMeOH (2.37 wt) and water (0.4 wt) and extracted with heptane (2.74 wt).The lower layer was extracted 9 times with heptane (2.05 wt). Theextracted solutions were combined and concentrated in vacuo to giveER-805815 (1.07 wt, 98.6%).

In an alternative method for workup of ER-805815, the crude organiclayer that is produced following brine wash and concentration is treatedwith MTBE (2.86 wt) and celite (0.5 wt). After stifling for 2.5 h,heptane (1.46 wt) was added over 2 hrs and the mixture stirredovernight. The precipitate was filtered. The filter cake was washed withMTBE/Heptane (1:1) (5 wt). The filtrate was concentrated in vacuo untilthe volume was decreased to about 3 volume. The residue was dissolved inMeOH (2 wts) and H₂O (6 wts). The mixture was extracted withheptane/MTBE (5:1) (3*6 wts). The organic layer was separated andconcentrated to provide ER-805815 which was used as is for the followingstep.

ER-805815 (1 wt) was dissolved in acetone (2.4 vol) and water (0.4 vol).N-Methylmorpholine N-oxide (0.62 wt, 2 eq) was added and the mixturecooled to 0-5° C., OsO₄ (0.15M in water, 0.065 vol) was added and thereaction was maintained at 0-5° C. The reaction mixture was stirred at0-5° C. for 12 hours. Water (0.2 vol) was added over 1 hour at 0-2° C.The mixture was stirred for one hour at 0-5° C. The product was filteredand the solids washed twice with pre-cooled (0-5° C.) acetone/water(1/1, v/v, 2×0.7 vol). The product was dried to afford ER-805816 (0.526wt, 52% yield, residual Os<17 ppm).

In an alternate method for preparing ER-805816, a solution of ER-805815(1 wt, 1 eq) in acetone (4 wt) was charged into a four-necked flask,then water (0.5 wt) was added at ambient temperature. To the mixture wasadded anhydrous N-methylmorpholine-N-oxide (0.38 wt, 1.2 eq). Potassiumosmate dihydrate (0.003 wt, 0.003 eq) was added portion-wise at 25 to35° C. while cooling with water. The mixture was kept at thistemperature for 4 hours. A solution of sodium thiosulfate 0.075 wt, 0.49eq) in water (0.5 wt) was added at ambient temperature, then the mixturewas stirred for 0.5 hour. The mixture was cooled to 0-5° C. and stirredfor 2 hours. The resulting precipitate was collected and the wet cakewas washed with methanol (0.6 wt) and water (1.5 wt) to obtain the crudeproduct (1.25 wt). The crude product sample was dried (0.611 wt). Thecrude ER-805816 (1.25 wt) was added to water (3.05 wt) and stirred for 2hours at about 25° C. The precipitate was filtered and washed with water(1.53 wt) to afford the crude wet cake (1.05 wt). The crude productsample was dried and sampled, ICP Os=37 ppm. The crude ER-805816 (1.05wt) was added to water (2.81 wt) and stirred for 2 hours at about 25° C.The precipitate was filtered and washed with water (1.4 wt) and methanol(0.45 wt) to afford the crude ER-805816 (0.736 wt). The wet cake wasdried crude product (0.56 wt, ICP (Os)=28 ppm). ER-805816 (0.56 wt) wasdissolved in acetone (1.76 wt) at 45 to 55° C. To the solution was addedactive carbon (0.027 wt) and stirred at same temperature for 0.5 hour.The mixture was filtered and the cake was washed with hot acetone (0.214wt). The filtrate was kept at 45 to 50° C. and water (0.83 wt) was addedover 10 minutes and temperature was kept at 40 to 50° C. during wateraddition. The mixture was cooled to 0 to 5° C. and stirred for 1.5hours. The white precipitate was filtered and washed with a solution ofacetone (0.17 wt) and water (0.22 wt) then dried to give ER-805816(0.508 wt, 0.49 eq, KF 5.0%, ICP (Os) 9.6 ppm).

ER-805816 (1 wt) was slurried in acetic acid (0.89 vol, 5.8 eq) andacetic anhydride (3.57 wt, 13 eq). Anhydrous ZnCl₂ (0.2 wt, 0.54 eq) wasadded. Reaction mixture was stirred for 24 hours 18-22° C. Reaction wasquenched into ice (5 wt) and water (5 vol). EtOAc (10 vol) was addedwith stifling and the aqueous layer is separated. The aqueous layer wasback extracted with EtOAc (10 vol). The combined organic layers werewashed sequentially with brine (10 vol), 5% aqueous NaOAc (6 vol), andbrine (6 vol). The organic layer was concentrated. The crude concentratewas dissolved in 25% EtOAc/hex (4 vol) and filtered through SiO₂. Thepad was washed with 25% EtOAc/hex (2×12 vol) and further 25% EtOAc/hex(48 vol). The organic layer was concentrated to give ER-805819 (1 wt,81%).

In an alternate method for preparing ER-805819, zinc chloride (0.2 wt,0.54 eq), acetic anhydride (2.75 wt, 10 eq), and acetic acid (1 wt, 6eq) were combined. The mixture was cooled to 15-20° C. ER-805816 (1 wt,1 eq) was added, maintaining the internal temperature at 15 to 30° C.The mixture was then stirred at 35-40° C. for 6 hours. The reactionmixture was cooled below 25° C. Methanol (3.2 wt, 4 vol) was addeddrop-wise maintaining reaction temperature below 25° C. Heptane (2.7 wt,4 vol) was added. Water was added (4 wt, 4 vol) maintaining reactiontemperature below 25° C. The mixture was stirred for 15 minutes, andthen the phases were separated. The lower layer was washed twice withheptane (2.7 wt, 4 vol) and the heptane layers were discarded. The lowerlayer was extracted twice with toluene (6.1 wt, 8 vol). The combinedtoluene layers were washed twice with 17 wt % potassium bicarbonateaqueous solution (0.82 wt KHCO3 in 3.98 wt water, 4.36 vol), twice withwater (4 wt), and concentrated. Methanol (3.95 wt, 5 vol) was added at25-30° C. and the mixture stirred for 10 minutes. Water (0.3 wt) wasadded at 25-30° C. The mixture was cooled to 0° C. and seeded. Themixture was stirred at 0° C. for 1 hour. Water (0.7 wt) was addeddrop-wise over 1 hour. Water (4 wt) was added drop-wise over 1 hour. Theresulting precipitated solids were filtered, and the filter cake washedtwice with a 0° C. methanol (1.03 wt) and water (0.7 wt) solution. Thecake was dried to afford ER-805819 (0.99 wt, 0.84 eq).

ER-805819 (1 wt) was dissolved in anhydrous acetonitrile (15 vol) andtreated with methyl 3-trimethylsilylpent-4-eneoate (0.93 vol, 2 eq). Thereaction mixture was cooled to 0-5° C. and BF₃.0Et₂ (0.54 vol, 1.95 eq)was added over 5 minutes, maintaining reaction temperature between 0-5°C. Reaction mixture was stirred 0-5° C. for 12 hours. Reaction wasquenched into saturated sodium bicarbonate (20 vol) with vigorousstifling. Extracted twice with EtOAc (2×8 vol). The combined organicswere washed with brine (12 vol) and concentrated to give ER-805821 (1wt, 88% yield, use as is).

In an alternate method for preparing ER-805821, ER 805819 (1 wt, 1 eq)and methyl 3-trimethylsilylpent-4-eneoate (0.93 vol, 2 eq) weredissolved in anhydrous acetonitrile (5.46 wt, 7 vol). The reactionmixture was cooled to 0-5° C. and BF₃.0Et₂ (0.54 vol, 1.95 eq) was addedover 5 minutes, while maintaining reaction temperature between 0-5° C.The reaction mixture was stirred at 0-5° C. for 20 hours then heptane(5.47 wt, 8 vol) was added at 0-5° C. The phases were separated and thelower layer treated with heptane (5.47 wt, 8 vol) at 0-5° C. Thereaction was quenched by dropwise addition of 7.4% potassium bicarbonateaqueous solution (0.64 wt KHCO₃ and 8 wt water), while maintaining thereaction temperature at 0-15° C. Toluene (8.65 wt, 10 vol) was added andthe mixture stirred for 30 minutes. The lower layer was separated andthe upper organic layer washed twice with water (10 vol) andconcentrated to afford ER-805821 as a crude oil (1.05 wt, 0.935 eq).

ER-805821 (1 wt) was dissolved in anhydrous THF (8.4 vol) and anhydrousMeOAc (2 vol). Triton B(OH) (3.6 vol) was added over 2 minutes, reactionmaintained 17-23° C. Reaction was stirred for 1.5 hour. Reaction mixturewas filtered. The filtrate was concentrated and passed through a pad ofSiO₂ (5 wt, EtOAc, 20 vol). The filtrate was washed with brine (2.2 vol)and evaporated to give ER-805822 (0.54 wt, 72% yield).

In an alternate method for preparing ER-805822, ER-805821 (1 wt, 1 eq,11.18 g, 21.81 mmol) was dissolved in anhydrous MTBE (4.4 wt, 6 vol.)and cooled to 0-5° C. NaOMe (28 wt % in MeOH, 0.564 wt, 1.5 eq) wasadded to the mixture over 1 hour at 0-5° C. and stirred for 3 hour atsame temperature range. The reaction was quenched by addition of aceticacid (0.188 wt, 1.6 eq.), maintaining 0-5° C. during addition. Themixture was stirred overnight then treated with a 5 wt % aqueoussolution of KHCO₃ (3 wt) and ethyl acetate (3.6 wt, 4 vol) at 0-5° C.,and then stirred for 15 minutes. After phase separation, the lower layerwas extracted with ethyl acetate (3.6 wt, 4 vol) twice. The combinedorganic layer was concentrated. To the residue was added acetone (2 wt,2.5 vol) and IPE (2 wt, 2.7 vol) and stirred overnight at 0-5° C. Themixture was filtered through Celite® (0.25 wt) and washed with acetone(2 wt). The filtrate was concentrated to afford the crude oil (0.55 wt).To the residue was added acetone (0.2 wt, 0.25 vol.) and IPE (0.54 wt,0.75 vol.) and stirred for 1 hour at 40-50° C. The solution was seededwith ER-805822 at room temperature and stirred overnight at roomtemperature. To the suspension was added IPE (1.27 wt, 1.75 vol.) over 2hours at room temperature. After stirring for 5 hours at roomtemperature, the precipitate was collected by filtration, and the cakewashed with acetone/IPE (1/10) (2 vol.). The obtained cake was dried ina tray-type chamber at 30-40° C. overnight to afford the desired productER-805822 (0.286 wt, 0.38 eq) in 38.0% yield from ER-805819.

In an alternative method for workup of crude ER-805822, the residuefollowing concentration of the final EtOAc solution was dissolved in IPA(2 wt) and the solution was heated to 50° C. Heptane (5 wts) was addedand the mixture was cooled to 20° C. and seeded. The mixture was stirredat 20° C. overnight. Heptane (10 wts) was added and the mixture wascooled to −5° C. in 30 min and stirred at −5° C. for 5 hrs. The mixturewas filtered and the filter cake was washed with heptane (2 wts). Thefilter cake was dried with air flow under vacuum to provide ER-805822(60%).

ER 805822 (1 wt) was dissolved in ethyl acetate or another appropriatesolvent (5 vol) and water (5 vol). NaIO₄ (0.58 wt, 1.05 eq) is addedportionwise over 30 min to 1 hour, maintaining reaction temperature0-10° C. Reaction is stirred for up to 2 hours. The reaction mixture wastreated with NaCl (1 wt) and stirred for 30 min at 0 to 10° C. Thereaction mixture was filtered and the cake is rinsed with ethyl acetate(2 vol). The phases were separated and the lower layer extracted withEtOAc (5 vol) three times. The combined organic layer was washed with20% aqueous NaCl (5 wt). The organic layer was concentrated to give ER804697 (1 wt). The residue was dissolved in toluene (2 vol) and thesolution concentrated. The residue was dissolved in acetonitrile (7 vol)and used for the next step.

NiCl₂ (0.025 wt) and CrCl₂ (2.5 wt) were charged to reaction vesselunder inert atmosphere. Anhydrous dichloromethane (5 vol) was charged.Stirring was initiated and the mixture was cooled to 0-3° C. AnhydrousDMSO (6.7 vol) was added with vigorous stifling over 45 minutes,maintaining temperature below 20° C. ER-804697 (1 wt) was dissolved inanhydrous dichloromethane (1 vol) and charged to the reaction vessel.The resulting mixture was warmed to 25° C. and1-bromo-2-trimethylsilylethylene (2.58 wt) was added neat over 20minutes. The reaction temperature was maintained below 45° C. Thereaction was stirred for 30 minutes at 25-35° C. following completeaddition. Methanol (5 vol) was added and the mixture was stirred for 10minutes. MTBE (33 vol) was charged and the slurry transferred into 1NHCl (25 vol) and water (10 vol). The mixture was stirred for 5 minutes.The aqueous layer was back extracted with MTBE (10 vol) and the combinedorganics washed sequentially with 0.2N HCl (17 vol), twice with 1% NaClsolution (2×17 vol), and brine (13 vol). The organic layer wasconcentrated and purified (SiO₂, 25 wt, 10 column vol EtOAc/Hex 1/3.5v/v) to give ER-804698 (0.53 wt, 61%).

In an alternate method, this reaction was performed in the presence ofthe chiral ligand ER-807363 in a manner substantially similar to thatdescribed for the preparation of ER-118047, infra.

In an alternate method for preparing ER-804698, DMSO (7 vol.) and MeCN(7 vol) were degassed and cooled to 0-10° C. The solution was treatedportionwise with CrCl₂ (10 eq, 3.47 wt) and NiCl₂ (0.1 eq, 0.037 wt)such that the internal temperature did not exceed 20° C. A solution ofER-804697 (1 wt, 1 eq) in MeCN (7 vol) and1-bromo-2-trimethylsilylethylene (5 eq, 2.5 wt) were added dropwise at0-10° C., not allowing the internal temperature to exceed 15° C. Thereaction mixture was stirred at 5-15° C. overnight. To the mixture wasadded methanol (5.5 wt), water (7 wts), and MTBE (5.2 wts). The reactionwas stirred for 1 hour and the lower layer was separated (layer 1). Tothe upper layer was added a premixed solution of NaCl (1.5 wts) andwater (13.5 wts). The mixture was stirred for 1 hour and the lower layerwas separated (layer 2). To the upper layer was added heptane (4.8 wts),methanol (2.8 wts), and a premixed solution of NaCl (1.5 wts) and water(13.5 wts). The mixture was stirred for 1 hour and the lower layer wasseparated (layer 3). The upper layer was drained and saved (organic 1).The reactor was charged with layer 1, methanol (2.8 wts), and MTBE (2.8wts). The mixture was stirred overnight. The lower layer was separatedand discarded. The upper layer was treated with layer 2. The mixture wasstirred for 1 hour and the lower layer was separated and discarded. Theupper layer was treated with layer 3 and heptane (4.8 wts). The mixturewas stirred for 1 hour and the lower layer was separated and discarded.The upper layer was drained and saved (organic 2). The reactor wascharged with layer 3, MTBE (0.8 wts), and heptane (2.7 wts). The mixturewas stirred for 1 hour and the lower layers was separated and discarded.The upper layer was combined with organic 1 and organic 2. The combinedorganics were filtered and concentrated at reduced pressure to affordthe crude ER-804698 which was purified by chromatography (SiO₂, 25 wt,10 column vol EtOAc/Hex 1/3.5 v/v) to give ER-804698 (0.67 wt, 57%yield).

In an alternate method of preparation of ER-804698, the crude materialis taken directly to the next step without purification.

ER 804698 (1 wt, 1 eq) was treated with AcOH (4.2 wts) and water (4.2wts). The mixture was heated to 90-97° C. for 100 min. The mixture wascooled to below 15° C. then washed with heptane (2×2.7 wts) twice below15° C. After phase separation, a mixture of 20 wt % aqueous KHCO₃solution (7.7 wts, 35 eq) and MTBE (5.95 wts) was added dropwise to thelower layer such that temperature does not exceed 15° C. After phaseseparation the upper layer was washed successively with 5 wt % aqueousKHCO₃ solution (0.2 wts), and twice with 5 wt % aqueous NaCl solution(2×0.2 wts). The organic layer was concentrated under reduced pressureand MTBE (1.49 wts) was added. The mixture was heated to 55° C. andstirred until dissolved. Heptane (1.00 wts) was added to the solutionand the solution was cooled to 40-45° C. Additional heptane (4.47 wts)was added to the solution and the solution was cooled to 5-15° C. andthen stirred overnight. The crystals were filtered and rinsed withheptane to provide ER-807023 (0.58 wts, 71% yield).

ER-807023 (1 wt, 1 eq) and MTBE (7.43 wts) were charged to a reactorunder a nitrogen atmosphere. To the reaction was added 2,6-lutidine(2.15 wts, 7.5 eq). To the mixture was added dropwise TBSOTf (2.47 wts,3.5 eq) at 0° C. The reaction mixture was stirred for 30 min at 0-10°C., then warmed to 23° C. over 1 hr and held at 23° C. for 16 hrs. MeOH(0.21 wts, 2.5 eq.) and water (14.8 wts) were added dropwisesequentially to the reaction mixture, maintaining temperature below 30°C. After phase separation, the upper layer was washed with 1N aqueoushydrochloric acid (16.2 wts), 5% NaCl aq. (14.8 wts), 5% NaHCO₃ aq.(14.8 wts), 5% NaCl aq. (14.8 wts), and 5% NaCl aq. (14.8 wts),respectively. The upper organic layer was concentrated by distillationunder reduced pressure to afford the crude ER-804699. MeOH (7.91 wts)was added and the mixture was heated to 50° C. for 30 min. The mixturewas cooled to 0° C. over 5 h, and then stirred overnight at 0° C. Thesolid was filtered, and the cake was washed with cold MeOH (4 wts) anddried to yield ER 804699 (1.42 wts, 74% yield).

Into a reactor under a nitrogen atmosphere was charged a solution ofER-804699 (1 wt, 1 eq) in toluene (2.60 wts). Acetonitrile (4.72 wts)was added. TBSCl (0.011 wts, 0.05 eq) was added. The reaction mixturewas warmed to 30° C. and the NIS was added (1.25 wts, 4 eq). Thereaction mixture was stirred at 22 hrs at 30° C. The reaction was cooledto 25° C. and the mixture of aqueous sodium thiosulfate and sodiumbicarbonate (10.35 wts) were added over 10 minutes keeping the internaltemperature below 30° C. The reaction was stirred for 30 minutes at 25°C. The aqueous layer was separated. The upper layer was washed twicewith 10% NaCl (aq) (2×9.9 wts). The organic layer was concentrated underreduced pressure to give crude ER-803895 that was purified using silicagel chromatography to provide ER-803895 (0.96 wt, 89.5% yield).

Example 6 Assembly of F-1a, F-2a, and F-3a and Preparation of B-1939 A.Preparation of (R) or(S)N-[2-(4-Isopropyl-4,5-dihydro-oxazol-2-yl)-6-methyl-phenyl]-methanesulfonamide

A pre-dried glass lined reactor was charged with triphosgene (1 wt., 1eq.) and anhydrous THF (2 vol.) and was cooled to an internaltemperature of −10° C. A second pre-dried glass lined was charged withER-807244 (1.27 wt., 2.5 eq.) and anhydrous THF (3 vol.) then cooled toan internal temperature of −10° C. The contents of the first reactorwere transferred into the second reactor at a rate such that internaltemperature did not exceed 15° C. After complete addition, the reactionwas stirred at an internal temperature of 0° C. for 1 hour and thengradually warmed to 25° C. A sparge of nitrogen was used for 18 hours toscrub away excess phosgene with trapping of the off-gases through a 2 NNaOH solution. MTBE (3 vol.) was added and the solvent removed bydistillation under N₂ purge at 40° to 46° C., adding more MTBE asneeded. Upon complete removal of the phosgene, the mixture was cooled toan internal temperature of 5° to 10° C. and the solution filtered withMTBE (3 vol.) washes to yield ER-807245 (1.12 wt., 0.97 eq.) as a whitecrystalline solid.

Into a pre-dried and inerted reactor 1, was added ER-807245 (1 wt., 1eq.) and anhydrous DMF (4 vol.). With stirring, the mixture was heatedto an internal temperature of 95° C. D or L-Valinol (1.05 eq., 0.61 wt.)was dissolved in anhydrous (DMF 1.3 vol.) in reactor 2 with heating toan internal temperature of 90° C. The contents of reactor 2 weretransferred into reactor 1 at internal temperature 90° C. CO₂ evolutionwas be observed and the reaction was vented with a N₂ bleed. Thereaction solution was stirred at 90° C. for 3 hours and then cooled toan internal temperature of 65° C. Then, an aqueous slurry of lithiumhydroxide (0.47 wt., 2 eq.) in water (2 vol.) was added to reactor 1 andthe suspension stirred at an internal temperature of 65° C. for 1 hour.The reactor was charged with water (5 vol.) cooled to an internaltemperature of ˜5° C. over 3 hours. The mixture was stirred for 8 hoursat internal temperature ˜5° C. and the desired product collected byfiltration with water (2×4 vol.) washes followed by n-heptane (2×3vol.). The product was dried under vacuum and N₂ flow at 35° C. for 24hours or until KF 250 ppm to yield ER-806628 or ER-808056 (0.80 wt.,0.60 eq.) as a crystalline solid.

A pre-dried and inerted reactor under nitrogen was charged withER-806628 or ER-808056 (1 wt., 1 eq.), pyridine (3 wt., 11.4 eq.) andDMAP (0.03 wt., 0.05 eq.). The reaction was cooled to an internaltemperature of −10° C. then methanesulfonyl chloride (1.46 wt., 3 eq.)was added at a rate such that internal temperature was below 15° C. Uponcomplete addition, the reaction was stirred at an internal temperatureof 0-15° C. for 1 hour and then slowly warmed to 25° C. over 2 hours.MTBE (2.6 vol.), was added followed by process water (2 vol.) at a ratesuch that the internal temperature did not exceed 35° C. The biphasicmixture was titrated with 6N hydrochloric acid, (˜1.9 vol.) portion-wiseuntil the pH of the aqueous layer=˜3 to 5. If pH went under 3, 30% (w/w)aqueous solution of Na₂CO₃ was added to back titrate to the desired pH.The phases were allowed to partition and the aqueous phase separated.All organics were combined with water (0.7 vol.) and the aqueous phasediscarded. The MTBE was distilled to a level of ˜2 vol. at atmospherepressure to constant by 55° C. and KF<500 ppm. Additional MTBE was addedif necessary. The solution was cooled to an internal temperature of5-10° C. with seeding when necessary to induce crystallization.n-Heptane (0.5 vol.) was added and the mixture stirred for 18 hours at5° C. ER-806629 or ER-807363 was collected by filtration with n-heptane(2×3 vol.) washes. A second crop of crystals was obtained byconcentration of the filtrates to ½ volume and cooling to 0° C. Thefilter cake was dried under N₂ for 18 hours. The crude weightedER-806629 was charged into a pre-dried reactor and MTBE (3 vol.) wasadded. The resulting mixture was heated to an internal temperature of45-50° C. for 45 minutes and then slowly cooled to 5° C. over 3 hours,with seeding when necessary. n-Heptane (0.5 vol.) was added and themixture stirred for 18 hours at an internal temperature of 5° C. Thesolid product was collected via filtration and n-heptane (2×3 vol.)washes then dried under vacuum at 35° C. for 24 hours to yield ER-806629or ER-807363 (1.7 wt., 0.57 eq.) as a crystalline solid.

B. Assembly of F-1a and F-2a and Intramolecular Ether Formation

An appropriately sized reactor 1 was charged with ER-807363 (1.82 wt,3.55 eq) and the atmosphere was exchanged for nitrogen. Anhydrous THF(15 vol) was added. In reactor 2, ER-806067 (F-1a, 1.14 wt, 1.1 eq) andER-805973 (F-2a, 1 wt, 1 eq) were combined and dissolved in anhydrousTHF (6.3 vol). With stifling, both reactors were sparged with nitrogenfor 30-45 minutes. Under an inert atmosphere, reactor 2 was charged withCrCl₂ (0.75 wt, 3.55 eq) and then heated to an internal temperature of30° C. Reactor 2 was charged with triethylamine (0.62 wt, 3.55 eq) at arate such that internal temperature did not exceed 45° C. After completeaddition, an internal temperature of 30° C. was maintained for 1 hour.After 1 hour, reactor 2 was cooled to 0° C. and charged in an inertfashion with NiCl₂ (0.02 wt, 0.1 eq), followed by the contents ofreactor 1 and the reaction was warmed to rt. Reactor 2 was cooled to aninternal temperature of 0° C. and then ethylenediamine (1.2 vol, 10 eq)was added at a rate such that the internal temperature did not exceed10° C. Note: An exotherm was observed. The reaction was stirred for 1hour, and then water (8 vol) and n-heptane (20 vol) were added and thebiphasic mixture stirred for 4 minutes and the layers allowed topartition. The organic layer was separated and the aqueous layer backextracted with MTBE (20 vol). The combined organic layers wereconcentrated in vacuo to a crude oil followed by an azeotrope withanhydrous THF (2×10.5 vol). The crude product was dissolved in anhydrousTHF (4.5 vol) and then stored at −20° C. until utilization in the nextstage.

The ER-808227/THF solution from the previous step was analyzed via KFanalysis. If KF<1000 ppm, then proceeded. If KF>1000 ppm, azeotroped invacuo with anhydrous THF (4.1 vol.). Repeated azeotrope untilspecification was met. The final solution meeting specificationscontained the dissolved crude ER-808227 in anhydrous THF (4.1 vol.).Once the specification was met, an appropriately sized inerted reactorwas charged with anhydrous THF (106 vol.) and the ER-808227/THF solutionfrom the previous step. The reactor was cooled to an internaltemperature of −15 to −20° C., then 0.5 M KHMDS in toluene (9.1 wt., 3.0eq.) was added at a rate such that internal temperature did not exceed−12° C. Approximately 4.5 eq. KHMDS was necessary to drive the reactionto completion. The reaction was reverse quenched into semi-saturatedammonium chloride (40 vol.) at an internal temperature of 0° C.n-Heptane (80 vol.) was added, stirred for 2-5 minutes, and then allowedto partition. The organic layer was separated, the aqueous layer wasback extracted with MTBE (70 vol.), then the organic layers werecombined and washed with saturated sodium chloride solution (70 vol.).The organic layer was separated and concentrated in vacuo. To the crudeconcentrate was added n-heptane (60 vol.). Note: ER-807363 precipitatedout of solution. The resulting suspension was filtered and the solidswashed with n-heptane (20 vol.). The filtrate was concentrated in vacuoto afford crude ER-806746 (˜4 wt.) as a brown oil: Note: When additionalER-807363 precipitated out of solution, the filtration process wasrepeated. The crude ER-806746 was purified via SiO₂ columnchromatography to yield ER-804027 (1.16 wt., 0.55 eq.) as a clearyellowish oil. The chromatography was performed as follows: the columnwas first flushed with sufficient MTBE to remove water then flushed withheptane to remove the MTBE. The ER-806746 was loaded onto the column asa solution in heptane then eluted from the column with heptane/MTBE(5:1) then heptane/MTBE (4:1) with the fractions monitored at 230 nm byUV detector.

A reactor was charged with ER-804027 (1 wt, 1 eq) and anhydrousdichloromethane (7.6 vol). The reactor was cooled to an internaltemperature of −78° C. and then 1 M DIBALH in dichloromethane (3.0 wt,2.25 eq) was added at a rate such that internal temperature did notexceed −60° C. Methanol (0.1 vol) was added at a rate such that internaltemperature did not exceed −60° C. Note: hydrogen gas evolved and wasdiluted with a stream of nitrogen. Upon complete addition, the mixturewas warmed to ambient temperature and then 1 N hydrochloric acid (10.6vol) and MTBE (25 vol) were added. The mixture was stirred for 20minutes and the layers allowed to partition. The organic layer wasseparated and the aqueous layer back extracted layer with MTBE (15.3vol). The organic layers were combined and washed with water (3 vol),saturated sodium bicarbonate (3 vol), and saturated sodium chloride (3vol), respectively, then concentrated in vacuo. The crude concentratewas purified via SiO₂ column chromatography to yield ER-804028 (0.84 wt,0.93 eq) as a white foam.

C. Incorporation of F-3a and Transformations to B-1939

ER-803895 (F-3a) was dissolved in anhydrous toluene (14 wt.) and cooledto <−75° C. under an argon atmosphere. DIBALH (1.5M in toluene, 0.95wt., 1.3 eq.) was added at a rate to maintain the internal reactiontemperature<−70° C. The resulting mixture was stirred for 30 minutesthen quenched with anhydrous methanol (0.13 wt., 3.2 eq.), maintainingthe internal reaction temperature<−65° C. The reaction mixture wasallowed to warm to −10° C. and transferred with an MTBE rinse (3.74 wt.)to a workup vessel containing 1N HCl (10.2 wt.). The mixture was stirredfor 30 minutes and the aqueous layer is drained. The organic phase waswashed sequentially with 1N HCl (10.2 wt.), water (10 wt.), saturatedaqueous sodium bicarbonate (10 wt.), and brine (10 wt.) thenconcentrated under reduced pressure. The concentrate was purified viasilica gel chromatography to afford ER-803896 (0.96 wt., 93% yield). Theproduct is stored at −20° C. under argon.

At 0° C., a solution of azeotropically dried sulfone ER-804028 (1.0 wt.,1 eq.) in anhydrous tetrahydrofuran (5 vol., 4.45 wt.) was treated withn-butyl lithium (1.6M in hexanes, 1.02 wt., 1.5 vol., 2.05 eq.) suchthat the internal temperature did not exceed 5° C. The mixture wasstirred at internal temperature 0 to 5° C. for 10 minutes then cooled to<−75° C. Azeotropically dried aldehyde ER-803896 (1.07 wt., 1.23 eq.)was dissolved in anhydrous hexanes (3.53 wt., 5.35 vol.) then cooled to<−75° C. The aldehyde solution was added to the ER-804028 anion bycannula such that internal temperature<−65° C. The mixture was stirredfor 45 minutes at internal temperature −78° C. then quenched by theaddition of saturated ammonium chloride (5 vol.), methyl tert-butylether (10 vol.), and water (5 vol.). The aqueous layer was discarded andthe organic layer concentrated under reduced pressure. The crudematerial was purified via C-18 reverse phase chromatography to affordER-804029 (84%, 1.57 wt.).

Sulfone-diol ER-804029 (1 wt., 1 eq.) was dissolved in wetdichloromethane (7.4 vol., 0.04 wt % water) and placed in a 20-25° C.water bath. Dess-Martin Reagent (0.67 wt., 2.5 eq.) was added in oneportion. The reaction mixture was quenched with saturated sodiumbicarbonate (10 vol) and 10 wt % aqueous sodium sulfite (10 vol.) andstirred for 30 minutes. The mixture was diluted with saturated sodiumchloride (10 vol) and extracted with MTBE (25 vol). The aqueous layerwas discarded and the organic layer concentrated and purified by silicagel chromatography to afford ER-804030 (0.9 wt., 90%). The material wasstored under inert gas atmosphere at −20° C.

To a pre-dried reactor under inert atmosphere was charged samariumdiiodide solution (2.5 eq.) and the solution cooled to internaltemperature<−70° C. ER-804030 (1 wt.) was dissolved in anhydrousmethanol (4.1 wt.) and anhydrous THF (2.3 wt.) and then cooled to <−70°C. ER-804030 was added to the cold samarium solution at a rate such thatthe internal temperature did not exceed −70° C. The reaction wasquenched with potassium carbonate/Rochelle's Salts/water (1/10/100;w/w/v, 15 vol.) and MTBE (5 vol.) such that internal temperature did notexceed −65° C. Upon complete addition of the workup solution, thereaction was warmed to room temperature and the mixture transferred to aseparatory vessel using the workup solution (20 vol. rinse) and MTBE (20vol. rinse). The aqueous layer was discarded, the organic layerevaporated, and the residue purified via silica gel chromatography toafford ER-118049 (0.77 wt., 85%). The product was stored at −20° C.under inert atmosphere.

A pre-dried reactor was charged with (S)-ligand ER-807363 (2.05 wt) andthe atmosphere was exchanged for nitrogen. The CrCl₂ (0.85 wt, 10 eq)was added in one portion followed by anhydrous acetonitrile (21.5 wt)and the mixture was warmed and maintained between 30° C. to 35° C.Triethylamine (0.7 wt, 0.96 vol, 10 eq) was added in one portion and themixture stirred for one hour. The NiCl₂ (0.09 wt, 1 eq) was added in oneportion, followed by the keto-aldehyde ER-118049 in anhydrous THF (2.43wt, 2.73 vol) over 30 minutes. The heat was removed then heptane (20.5wt, 30 vol) and Celite® (1.5 wt) were added. The mixture was stirred for5 minutes and filtered over a pad of Celite® (15 wt) and the Celite® padrinsed with heptane (7.3 vol) and acetonitrile (5 vol). The filtrate wastransferred to a separatory funnel and the lower layer removed. Thecombined heptane layers were washed with acetonitrile (maximum 47.2 wt,maximum 60 vol) as necessary. The heptane layer was evaporated underreduced pressure and the product purified by silica gel chromatographyto afford ER-118047/048 (0.64 wt, 70%).

Allyl alcohol ER-118047/048 was dissolved in dichloromethane (0.04 wt %water, 9 vol) and the reactor was placed in a water bath (20° C.) andthe solution was treated with Dess-Martin Reagent (0.48 wt, 1.5 eq). Thereaction mixture was treated with saturated aqueous sodium bicarbonate(9 vol) and 10 wt % aqueous sodium sulfite (9 vol) then stirred for 20minutes and transferred to a separatory funnel with DCM (10 vol). Theaqueous layer was discarded, and the organic layer evaporated to aresidue. The crude material was purified by flash chromatography(prepped with 3 CV (1:1 (V/V) DCM/heptane, the material was loaded with1:1 DCM/heptane then eluted with 10/10/1 heptane/DCM/MTBE). Theproduct-containing fractions were concentrated and stored under inertatmosphere at −20° C.

Alternatively, the oxidation of ER-118047/48 to form the di-ketoneER-118046 was accomplished as follows. A flask was charged withER-118047/48 (1 wt, 1.0 eq) and toluene (10 vol) and DMSO (0.15 wts, 2.5eq) were added at room temperature. Et₃N (0.31 wts, 4.0 eq) was addedand the solution was cooled to −15° C. TCAA (0.33 wts, 1.4 eq) was addedneat and the reaction warmed to 0° C. then stirred for 10 minutes at 0°C. The reaction was stirred for additional 10 minutes then was quenchedwith IPA (0.15 vol). The reaction was stirred at 0° C. for 10 minutes.1N HCl (5 vol) was added over 2 minutes, and the reaction was warmed toroom temperature and diluted with MTBE (5 vol). Two clear layers formedand the aqueous layer was removed and discarded. The organic layer waswashed with 5 vol of 5% bicarbonate (aqueous), concentrated to a heavyyellow oil on a rotary evaporator and purified by silica gelchromatography (91% isolated yield).

Into an appropriately sized reaction vessel (vessel A) was chargedimidazole hydrochloride (0.39 wt, 5 eq) followed by 1 M TBAF in THF (7.6vol, 10 eq) at ambient temperature. The resulting mixture was stirreduntil it is homogenous (15-30 minutes). Into a second reaction vessel(vessel B) was charged ER-118046 (1 wt, 1 eq) and THF (33 vol). Thecontents of vessel B were placed under an inert atmosphere and stirreduntil ER-118046 was fully dissolved. The contents of flask A(TBAF/Imidazole) were charged as a single portion into flask B(ER-118046/THF). After 3-4 days, the reaction solution was loaded onto acolumn and purified by silica gel chromatography.

The dried ER-118064 (F-12 wherein R¹ is MeO) residue was dissolved inanhydrous dichloromethane (28 vol) under a nitrogen atmosphere andtreated with PPTS (1.0 wt, 5.2 eq) in one portion. After 30-90 minutes,the reaction mixture was directly loaded atop an appropriate column andpurified by silica gel chromatography. The desired fractions ofER-076349 were concentrated in vacuo. The material resulting from theconcentration of all pure fractions was azeotroped twice from toluene(20 vol), affording ER-076349 as a crunchy colorless solid/foam (0.44wt, 0.79 eq after correction for residual toluene).

In a clean dry reaction vessel (flask C) ER-076349 (1 wt, 1 eq) wasdissolved in anhydrous toluene (20 vol) and concentrated to drynessunder reduced pressure. The substrate was re-dissolved in anhydroustoluene (20 vol) and concentrated to dryness. The substrate wasdissolved in DCM (5 vol), and the solution placed under an argonatmosphere. Collidine (0.66 wts, 4.0 eq) was added as a single portion.Pyridine, as a solution in DCM (Flask B), was added as a single portion(5 mole %). The resulting mixture in flask C was cooled to an internaltemperature of −20 to −25° C. A DCM solution of Ts₂O was added drop-wisekeeping the internal temperature below −16° C. (1.02 eq). The reactionwas stirred at −20 to −25° C. for 80 minutes then warmed to 0° C. over20 minutes and stirred for an additional 20 minutes. The reaction wasquenched with water (2 vol). The bath was removed, and the reactionallowed to warm to room temperature (15-20° C.) and stirred (20minutes). The reaction was rinsed to a larger vessel using the IPA (100vol) and aqueous ammonium hydroxide (100 vol) was added to the reaction.The reaction was stirred at room temperature for 15-36 hours, monitoringfor the disappearance of the tosylate (ER-082892) and epoxide(ER-809681) which formed in situ. The reaction was concentrated todryness or near dryness at reduced pressure. The resulting material wasdiluted with DCM (25-40 vol) and washed pH 10 buffer (NaHCO₃/Na₂CO₃(aq), 10 vol). The aqueous phase was back extracted with 25 vol of DCMand the combined organic layers were concentrated to dryness. Theresulting free amine was purified by silica gel chromatography using abuffered ACN/water mobile phase. The pooled fractions were concentratedat reduced pressure to remove ACN. The resulting aqueous layer wasdiluted with DCM (40 vol) and with 30 vol of a pH 10 buffered stocksolution (NaHCO₃/Na₂CO₃). The layers were mixed well and separated. Theaqueous phase was back extracted with 25 vol of DCM and the combinedorganic layers were concentrated to dryness. The resulting free aminewas polish filtered as a solution in 3:1 DCM/pentane and concentrated todryness (0.80 wts) to afford B-1939.

While we have described a number of embodiments of this invention, it isapparent that our basic examples may be altered to provide otherembodiments that utilize the compounds and methods of this invention.Therefore, it will be appreciated that the scope of this invention is tobe defined by the appended claims rather than by the specificembodiments that have been represented by way of example.

The invention claimed is:
 1. A compound of formula F-1:

wherein: each of PG¹ and PG² is independently a suitable hydroxyl protecting group, taken with the oxygen atom to which it is bound, selected from the group consisting of an acetate, a carbonate, a sulfonate, a silyl ether, an alkyl ether, an arylalkyl ether, and an alkoxyalkyl ether, or PG¹ and PG² are taken together, with the oxygen atoms to which they are bound, to form a diol protecting group; R¹ is R or OR; R² is CHO or —CH═CH₂; and each R is independently hydrogen, C₁₋₄ haloaliphatic, benzyl, or C₁₋₄ aliphatic, provided that, when R¹ is OMe, then PG¹ and PG² do not form an acetonide group, or PG¹ and PG² are H, R¹ is OH, and R² is —CH═CH₂.
 2. The compound of claim 1 having the formula:


3. The compound of claim 1 having the formula:


4. The compound of claim 3 in crystalline form.
 5. The compound of claim 1 having the formula:


6. The compound of claim 5 in crystalline form. 